A Guide for Maintaining Pedestrian Facilities for Enhanced Safety

5 Maintenance Measures

This chapter summarizes the common repair and seasonal maintenance practices for pedestrian facilities based on research conducted for the guide. The first section provides a summary of the repair methods, and how they are used for the range of pedestrian facilities. Part two includes common day-to-day seasonal maintenance methods along with recommended practices. The treatments are presented in order from the easiest to implement to the more complex and difficult.

5.1 When is Maintenance Necessary for Sidewalks, Paths, and Curb Ramps?

Chapter 3 of this guide outlined the problems that drive the need to maintain pedestrian facilities. The range of potential needs requiring servicing is expansive. Infrastructure maintenance needs involve the repair of sidewalk slabs or path segments by grinding, crack filling, and patching. In many cases the only solution is to replace sidewalks or resurface paths. Generally when surface conditions degrade to a point where tripping hazards exist or worsening running or cross slope conditions are making routes inaccessible, maintenance needs to occur. Maintenance is also necessary to respond to seasonal conditions such as fallen snow or overgrown vegetation. Every community should establish thresholds that trigger a response to these problems. Those thresholds should be informed by accessibility guidance using the criteria developed by the Access Board. Section 4 of this Guide outlines the thresholds, standards, and inspection techniques that should be in place. In summary, maintenance is necessary for sidewalks, curb ramps, and paths when an acceptable threshold is exceeded in the following categories. Additionally, seasonal maintenance is also required and is covered in detail in 5.6.

• Displacements
• Surfacing issues such as cracks, holes, surface deterioration
• Grades and cross slopes
• Other issues (detectable warning fields, ramp problems, etc.)

A large percentage of communities in many states employ a sidewalk replacement program that cycle through a community, focusing on different neighborhoods over a number of years. Over a period of years the entire community will be covered and the cycle begins again. This type of program often uses higher standards and tighter thresholds than spot repair programs. For example, a cracked sidewalk that currently exhibits no tripping hazard or other form of deterioration would not trigger a spot treatment, but would be addressed as part of a rotating sidewalk replacement program.

5.2 Maintenance Repair Methods for sidewalks and paths

Maintenance practices involving infrastructure can be categorized into three main groups: temporary; short term measures; and longer term measures lasting many years (in some situations even over ten years). Temporary measures are made just to reduce tripping hazards and last less than a year. Short term measures typically last one to five years and are intended to extend the life of the sidewalk segment until it is replaced. Long term measures include sidewalks replacement. When sidewalks are replaced as part of a street project, the work may be considered higher order than simple maintenance, thus falling under the definition of alterations under the ADA.

Temporary Maintenance Measures

Temporary repair measures may include wedging or patching a sidewalk with asphalt or a quick-mix cement. The temporary repair should alleviate the most hazardous concerns until a more permanent repair is performed later

Short Term Maintenance Measures (Repairs)

Several maintenance techniques will last one to five years for sidewalks and paths. These include patching (5.2.1), wedging (5.2.3), grinding and horizontal cutting (5.2.4), mud-jacking (5.2.5), and overlays.

Long Term Maintenance Measures (Replacement)

The universally accepted long term maintenance technique is sidewalk replacement. However, many communities have success with grinding (5.2.4) and mud-jacking (5.2.5) as longer term solutions. Horizontal cutting (5.2.4) is a newer technique that is similar to grinding and should have the same success rate as grinding. The problem in considering grinding, mud-jacking and horizontal cutting as longer term solutions is that the underlying problems associated with these fixes may continue to be an issue. For example, if a sidewalk sags and mud-jacking is used to correct the problem, the original unstable base may cause continued sagging. Also, some repairs will degrade the overall quality of the sidewalk. For example, grinding and horizontal cutting may be a lasting solution to a tripping hazard, but may leave one or two sidewalk panels with a cross slope of greater than two percent or with warped transitions between panels.

Provided below are the common maintenance responses to on-going infrastructure problems along with recommendations for their use. Not every community will have the same toolbox or use maintenance measures in the same way. Much depends on the current stock of facilities in a community – brick sidewalks will require different repair methods than concrete. Secondly, maintenance problems vary by community, state, and region and could be affected by underlying soils and to climate. For example, southern Arizona does not use any asphalt patching for sidewalks because of the extreme heat. This is especially true for seasonal maintenance; while Miami may face problems with encroaching vines, Duluth, Minnesota is more likely to be concerned with heavy snowfall. Additionally, many communities are focused on sidewalk and path preservation. Different treatments and standards are used to try to preserve pavements than are used to take corrective measures.

Provided below are the common maintenance responses to on-going infrastructure problems along with recommendations for their use. Not every community will have the same toolbox or use maintenance measures in the same way. Much depends on the current stock of facilities in a community – brick sidewalks will require different repair methods than concrete. Secondly, maintenance problems vary by community, state, and region and could be affected by underlying soils and to climate. For example, southern Arizona does not use any asphalt patching for sidewalks because of the extreme heat. This is especially true for seasonal maintenance; while Miami may face problems with encroaching vines, Duluth, Minnesota is more likely to be concerned with heavy snowfall. Additionally, many communities are focused on sidewalk and path preservation. Different treatments and standards are used to try to preserve pavements than are used to take corrective measures.

5.2.1 Patching

Patching is a common and often effective repair when small sidewalk corners have broken off or minor gaps have formed between sidewalk panels. It is temporary and most often done in asphalt. When a concrete filler is used, it is best to undercut the hole to allow the patch to bond more permanently with the existing sidewalk. As seen below, asphalt patching (as well as wedging) leaves a lip that is at least as significant as the size of aggregate that is used in the material. Choosing asphalt as a patching and wedging material is seldom done in the southwest parts of the U.S. because of the incompatiability of the material with high sustained temperatures.

Figure 20: Missing areas of concrete have been marked for repair.

21: The areas have been temporarily repaired with asphalt patches. Note the patching material overlaid on the concrete extending beyond the hole.

 

Material:	Asphalt, but sometimes a concrete-type filler (mortar or composite material consisting of vinyl or epoxy mix)
Most suitable:	Small holes of less than one foot
Least suitable:	Large holes or large surface areas
Durability:	Varies significantly based on repair method, material, depth of hole or crack, and underlying stress placed on the sidewalk. Generally less than several years.
Characteristics:	Hot mix asphalt is easy to use as a filler, but has a very short life. Cold asphalt mix is an even more temporary repair material most often only suitable for a winter to spring seasonal repair. Mortar or concrete-type filler has a longer life, but is time-consuming to apply and is rarely used by muncipalities.
Recommendations:	Suitable as a temporary repair. Highly recommended as a quick-response corrective measure when tripping hazards are reported until a more permanent repair can be made.
Technique:	Clean hole extremely well to provide the best bond. When using asphalt or a concrete-type filler it is best to square off the sides of the hole. For concrete-type filler, undercutting the sides of the hole is recommended and will elongate the life of the patch. A bonding material or concrete adhesive such as a acrylic resin-a milky fluid-can be used to help with bonding a concrete filler or a mortar mix to the existing concrete. The material should be leveled- off and tamped down for asphalt and finished smooth using a trowel for concrete. If a large hole is filled for a sidewalk connected to a driveway apron and a concrete patch is used, the mix should contain aggregate to give the patch more compact strength because of vehicle loads crossing on top of the sidewalk.

5.2.2 Cracking Repairs

Cracking of concrete sidewalks can take many forms. Because of the deformation forces constantly at work below the grade of sidewalks and paths (discussed in Section 3), expansion joints are used to control cracking. But this is only partially effective. Common types of cracks are edge, alligator, and longitudinal cracking. Alligator cracking is characterized as typically fine, longitudinal hairline cracks running parallel to each other with none or few interconnecting cracks. These are very difficult to treat with a filler unless a laborious routing procedure is used. Longitudinal cracking occurs along the length of the sidewalk, usually in the middle third of the sidewalk, and can extend through several expansion or control joints. Transverse cracks occur across the width of the sidewalk due to non-uniform subgrade compaction, especially where sidewalks are subjected to high vehicle loads such as where driveways cross sidewalks. Longitudinal and transverse cracks are wider thus somewhat easier to rout and fill than alligator cracking.

Figure 22: Cracking can cause trip
hazards as well as hazards for
bicyclists and wheelchair users.
This crack is on a shared use path.

Evaluating the type of cracking and the cause will determine the success rate for crack repairs. If a sidewalk has alligator cracking because of poor sub-base drainage or serious structural damage, crack sealing is not a good option. Sealants used for other forms of cracking should be thought of as only preventive in nature. Although new sealants have tremendous bonding power, they will not hold two sidewalk segments together; they are only effective in keeping water and moisture from descending into the void. If cracks are currently creating a tripping hazard or will very soon, sidewalk replacement is a better and necessary option. Under the best of scenarios, sealing cracks buys you time and helps defer more costly repairs.

Sidewalk cracks are rarely filled by agencies. This is in contrast to crack sealing being quite common place for concrete streets. There are several reasons for this, but this is most attributable to the time consuming nature of this repair, especially given that the cost and time it would take to replace sidewalk sections altogether is fairly comparable.

Material:	Polymer-modified and asphalt rubber sealants for concrete and asphalt sidewalks and paths. Also, mortar mix for larger cracks in concrete sidewalks
Most suitable:	Cracks that are a quarter inch or greater but less than a half inch
Least suitable:	Large cracks of more than a half inch. Cracks with widths greater than this are not in compliance with the ADA so if the crack material settles or pops out, an accessibility problem is created.
Durability:	Varies significantly based on repair method, depth of crack, and underlying stress placed on the sidewalk. Generally lasts less than several years and will only prevent water infiltration.
Characteristics:	Cracking sealants themselves can last years, however, their efficacy is based not only on the material life, but how well they hold their bond to the concrete or asphalt. Sealants that are manufactured today for roadway applications are highly engineered products formulated to perform in a range of climatic conditions – they need to remain solid in the summer and still be flexible in freezing temperatures. The Strategic Highway Research Program tests materials and application devices.
Recommendations:	Crack sealing and repair is rarely used by agencies for sidewalks. However, crack sealing is more commonly used for asphalt paths. Costs associated with routing out cracks to prepare them for mortar or a sealant is expensive and temporary especially compared to the cost of sidewalk replacement efforts.
Technique:	Cracks are commonly routed to accept a sealant or a masonary material, but the cracks must be completly clean and dry when a sealant or masonary material is used. Two techniques are used. For deep cracks a backer rod may be necessary. For sealants, the material is simply applied to the clean, dry, and routed crack. The other way, for use with concrete only, is to undercut the crack and use a concrete or masonary material. This will help make a structural bond that could aid in the shifting and uplifting of the concrete pieces. Despite the laborous nature of these repairs, most often these repairs are only temporary and are recommended only as such.

5.2.3 Wedging

Wedging entails the placement of an asphalt or concrete filler placed in advance of a heaved or displaced section of a sidewalk or shared use path to essentially provide a ramp and remove a tripping hazard. This is most often applied where there is a formed or saw joint in a concrete sidewalk and the concrete has uniformly lifted at the joint. If done properly to a sidewalk that is not severely displaced, it can be made ADA accessible. The wedge on the left in the photo (Figure 24) is just a few days old, while the wedge on the right is likely to be several years old with significant deterioration illustrating the short term nature of this technique. Also note the gradual grade with the wedge on the left consistent with a grade of 5% or less and in keeping with the ADA draft guidelines for public rights-of-way.

Figure 23: Wedge has been placed to mitigate the hazard caused by a raised sidewalk slab. Note the extensive and appropriate ramping of the wedge.

Figure 24: A small wedge may still create a hazard or be difficult to navigate in a wheelchair. This wedge had deteriorated over time.

 

Material:	Asphalt, but sometimes a concrete-type filler (mortar or composite material consisting of vinyl or epoxy mix). Cold mix asphalt mix is applied as a very temporary seasonal repair because the material often lacks adequate bonding capabilities.
Most suitable:	For temporary repairs when sidewalks lifts by more than a half inch to less than 2 inches.
Least suitable:	As a long term repair or when sidewalks displace by less than half inch. Or when the sidewalk displacement is more than a couple of inches. This will require a very long ramp (2 feet or greater) leading to the displacement.
Durability:	Varies somewhat on repair method, material, how well the asphalt material is compressed (hot mix), any continued shifting of the sidewalk pieces, and winter maintenance (especially plows mounted on pick-up trucks running over the wedge).
Characteristics:	Asphalt is easily to use as a wedge filler, but has a very short life and it will be noticeable in appearance because the material has a texture and color that will not match concrete. Cold asphalt mix is an even more temporary repair most often only suitable for a winter to spring repair. Mortar or concrete-type filler has a longer life, but is time-consuming to apply and has a comparatively long set-up time. It is rarely used by muncipalities.
Recommendations:	Suitable as a temporary repair. Highly recommended as a quick corrective measure when tripping hazards are reported until a more permanent repair can be made later in the season or within a year depending on the slope and integrity of the wedge.
Technique:	The sidewalk area to be filled with the wedge material needs to be cleaned of any loose material. Often a stiff broom or blower is used to clean debris from the sidewalk. Level off and tamp down for asphalt hot mix. A mechanical tamper should be used, but if the wedge is very small in length (less than a foot), a hand tamping tool can be used.

5.2.4 Grinding and Horizontal Cutting

Another set of treatments that can be used for heaved concrete sidewalk and path segments is grinding and cutting. Displacement of concrete sidewalk and paths will often occur at the joints. More and more communities are using grinding and cutting methods to make more permanent repairs to these types of displacements.

Grinding and horizontal cutting are similar treatments. New cutting technology is allowing tighter tolerances with horizontal cutting saws. The photo on the left is of a horizontal cut at a sidewalk panel displacement at a joint. Note that the panel has uniformly lifted allowing a straight cut across the width of the panel. The panel being cut has not settled from one side to the other, just lengthwise. Therefore, there is no change in the cross slope, making cutting or grinding an appropriate treatment for this sidewalk displacement. The panels depicted on the right show uneven settling, so grinding or cutting will eliminate the tripping hazard, but will likely leave a warped condition. ADA draft guidelines accept grinding and cutting for displacements of between ¼ in and ½ in. If over a ½ in, the repair has to be at the grade of a ramp – maximum of 8.3%. For instance, if the heaved sidewalk segment leaves a displacement of ¾ inch at the joint, the grind or cut would have to taper back approximately nine inches for the repair to be ADA compliant and considered permanent.

Grinding is also done to asphalt. On paths and sidewalks root pop-ups and minor heaves are often ground down.

Figure 25: A raised sidewalk block has been ground down to provide a smoother transition.

Figure26: The diagram shows how an unevenly raised slab can be ground to provide a smoother transition.

 

Material:	Grinding can occur with either asphalt or concrete, but is much more common with concrete. Horizontal cutting occurs almost exclusively with concrete
Most suitable:	For permanent repairs when sidewalks displace by a quarter inch to a half inch or for a temporary repair when sidewalks displace between a half inch and 1 inch. Repairs of a half inch or less can be provided at a one to one taper.
Least suitable:	As a long term repair when sidewalks displace by more than 1/2 inch. Any displacement of more than a half inch will require a longer ramp at 8.3% (at least 6 inches)
Durability:	The aggregate in the sidewalk is exposed and the thickness of the slab reduced, but the sidewalk and cut will still maintain its integrity. Repairs done appropriately and expertly can be considered permanent fixes.
Characteristics:	A horizontal cut will leave the appearance of a very smooth cut surface with exposed aggregate (the saw will cut right through the stones in concrete). Grinding will leave a much rougher texture and will show the grinding pattern of the apparatus used.
Recommendations:	Suitable as a temporary repair and even permanent repair based on the size and angle of displacement. Highly recommended as a permanent corrective measure when the displacement is between a quarter inch and a half inch. The sidewalk being ground down should be maintained at 2% or less cross-slope. Care should also be taken not to grind concrete slabs past minimum recommended thickness so as not to compromise the slab's integrity.
Technique:	This is a machine based operation. There are numerous pieces of equipment on the market that will grind and cut, but the technique is straightforward – grind the lip of a heaved section down or use a specially designed concrete saw to cut horizontal to the grade of the sidewalk to lop off the offending sidewalk lip.

5.2.5 Mud-jacking, Concrete Raising or Slab-jacking

This repair method lifts concrete sidewalk slabs back to their original position by ;pressure injecting cement or non-cement material under the sidewalk. Holes are drilled through the slab and grout is injected to raise the concrete slab or to fill the voids under them. It is important to identify the reason for the voids so that mud is not inadvertently pushed into storm sewers or other utilities. Although it is less costly than replacement, it is only effective on sunken sidewalks. Of the communities contacted for this report, few were using this repair method, even though it can have long term success. The photo in Figure 27 of a mud-jacked sidewalk segment in Madison, Wisconsin, has been in good shape and in compliance to standards for more than 20 years.

Figure 27: Graphic detail of how the mud-jacking process works

Figure 28: These panels were mud-jacked more than 20 years ago and are still in good condition so if done properly this can be a permanent fix.

Material:	Mudjacking is done only to concrete sidewalks and paths. A concrete type "mud" or mixture is used as the material injected under the concrete slabs.
Most suitable:	For sunken sidewalk segments where confidence is high that the slabs will not simply sink again.
Least suitable:	When the sunken sidewalk segments have a short life and will need to be replaced soon anyway or the underlying structural problem cannot be counter acted.
Durability:	Repairs done appropriately and expertly can be considered permanent fixes.
Characteristics:	Small holes are detectable after mudjacking, otherwise the repair leaves the sidewalk appearing at a constant running grade and cross slope matching adjacent and untouched sections.
Recommendations:	Suitable as a long term repair, but typically mudjacking is relatively expensive often approaching the cost of sidewalk replacement so older sidewalk segments should be avoided unless communities can use this technique at a very modest cost. Recommended as a permanent corrective measure when the sidewalk is sunken by more than ½ inch and the panel can be lifted back into place with the correct sideslope. Care should be taken to identify the cause of settlement and ensure that issue has been addressed prior to mudjacking.
Technique:	The concrete sidewalk slab is lifted back to its original position by pressure injecting a concrete-like material under the sidewalk. Holes are drilled through the slab and the liquid material is injected to raise the concrete slab or to fill the voids under them. It is also possible to hydraulically lift sidewalk segments with a series of jacks.

5.2.6 Sidewalk and Path Replacement

Although many repairs can provide temporary solutions to sidewalk and path problems, especially tripping hazards, at some point it becomes necessary to completely replace sidewalks or path sections (panels). This involves the entire removal and replacement of sidewalk sections or small path segments. When individual sidewalk sections or perhaps even a couple panels are being replaced at a time, this activity is considered as a maintenance effort.

It is imperative that agencies understand the underlying causes of sidewalk failure. Section 3.2.1 of this guide identified the deformation forces at work that cause sidewalk failures. Many of the failures for sidewalks are caused by poor subgrade or tree roots. Without addressing the underlying problems, the sidewalk being replaced will have a shortened life.

There are two basic approaches to replacement: zone-by-zone replacement and spot replacement. Often communities will combine both into a replacement program. Based on the research conducted for this report, the zone-by-zone approach to sidewalk replacement is common in Midwestern states. It is typically cost-effective for moderately sized or larger communities to manage an annual program for the replacement of sidewalk sections in sub-areas or zones of their community. Communities often put this in action on a four- to ten- year cycle. It has the added benefit of not only addressing all of the defects, but most of the accessibility issues as well.

Another common way sidewalk replacement is used is to make spot repairs when hazards are reported. In some communities the replacement of sidewalk sections (panels) is the only repair that is considered. Fifteen percent of the communities contacted for this Guide's research report were using this approach. Several in this group stated that they respond only to reported hazards on a community-wide basis and did not have a formal program in place. However, in these cases, their own city crews were replacing the sidewalks on the spot since these communities were funding 100% of the repairs. Not having to levy property assessments for these repairs significantly aided their ability to respond quickly to the hazards, and in some cases, they were replacing sidewalks in as few as three days to a week after they were reported.

Although a significant number of communities use sidewalk replacement on a spot basis, many communities (and a slightly higher percentage in our research) combine this with the longer-term zone-by-zone repairs. This way, problems outside the targeted zone(s) can be addressed more immediately while a sidewalk replacement program is cycling through the community. Some of the smaller communities studied in the research were able to manage such a program over the entire community on an annual basis. This model requires a significant commitment to inspection (see Chapter 4 on inspection and inventory).

Nearly all of the communities reached for this study indicated that they take full advantage of street reconstruction projects to replace sidewalk segments. When combined with street reconstruction, sidewalk replacement can generally be completed at a lower unit cost. Because of the nature of these repairs – often involving the replacement of very long segments of sidewalk using tighter inspection standards – sidewalk replacement falls into rehabilitation or reconstruction definitions, the same as the street.

Material:	The replacement material used will almost always match the material used for the connecting sidewalk or path segments. Replacement material for most sidewalks is concrete and asphalt for paths.
Most suitable:	Replacement is the best and longest term repair solution for displaced sidewalks and paths. Although temporary repairs can be used to delay sidewalk and path repairs, only replacement ensures the best method for addressing displaced sidewalks and more easily permits the use of appropriate grades for the cross-slope and running slope of the sidewalk or path.
Least suitable:	When simple repairs, such as grinding and horizontal cutting, can result in significantly elongating the life of the sidewalk or path and are considered effective.
Durability:	Replacement of sidewalks and paths are considered permanent fixes.
Characteristics:	Smaller segments of sidewalk, path, or curb ramps removed and replaced with new concrete or asphalt (only concrete for curb ramps).
Recommendations:	The complete replacement of material for sidewalks and paths allows the best possible result for meeting standards and for providing the longest lasting repair. It is recommended where sidewalks and paths cannot be repaired through less expensive means or the displacement of the sidewalk or path is so significant that replacement is the only feasible measure. Replacement is also recommended where smaller defects may appear (that may not present a tripping hazard such as surface cracking), but a circulating sidewalk replacement program is targeting that area of the community for that year.
Technique:	The damaged sections are removed either by hand or a small skid-steer loader after they are broken up by a jack hammer. For projects where many concrete sidewalk pieces are being removed, a heavy piece of equipment is used which makes use of a strong, telescoping boom with an attached digging bucket that can lift individual sidewalk panels from the sidewalk grade. After removal, steel or wooden forms are pinned in place. The existing grade is adjusted and in some cases additional fill is used to level off the grade. Tree roots are very carefully cut if at all necessary. The base surface is mechanically tamped if fill is added (with sidewalk replacement programs, the sections of sidewalk removed are too small to make use of a roller). Concrete is then poured into the grade between the two forms and the existing functional sidewalks. A strike-off board is used to level off the concrete from one existing sidewalk to the other where the old sidewalk exists. Finishers will trowel the surface of the concrete to push the aggregate from the surface and to move more of the mortar or "slurry" to the top. This provides for a smooth finish and aids in the final step of finishing which entails the use of a broom to finish the concrete with light brush marks made perpendicular to the direction of pedestrian travel. When asphalt is used, the removal is similar, but if the size of the removed section is limited, the replaced pavement can be completed by hand using shovels and an asphalt lute to level the asphalt. A hand tamping machine or roller is used to compact the asphalt. If the segments are longer, as is often the case with paths, paving equipment is used. This provides a far superior surface. Dump trucks are backed to the paving equipment which has a hopper for the asphalt. When paving equipment is being used, rollers will be used to compact the material.

5.2.7 Bricks and Pavers

Figure 29: Damaged pavers have been repaired
with asphalt to alleviate a hazard.

Bricks and pavers are materials which are considered a "segmental material" because each paver is separate and is often not tied or bonded together the way a concrete slab is formed and functions. When there is an underlying problem in the subgrade, it is not unusual to have just one or two bricks become displaced creating a localized tripping hazard. In contrast, concrete sidewalks might be able to withstand smaller more localized pressures until a time the entire slab faults or cracks. Gaps between bricks and pavers might also cause problems in greater frequency than with concrete and asphalt sidewalks simply because of the greater number of potential gaps that exist.

Bricks and pavers should be initially installed so they are easy to reset or replace. Of importance from an accessibility standpoint, bricks and/or pavers can cause vibrations that are painful for pedestrians who use mobility aids such as wheelchairs. Again, the design of the sidewalk can reduce this problem based on the pattern of the bricks/pavers, the edges used for the bricks/pavers, and the joint width that is used. Because of these issues, when the time has come for sidewalk replacement many communities are replacing bricks and pavers with concrete and then using bricks for sidewalk borders.

Material:	Bricks are made from fired clay and most pavers are made from a concrete mix, but can also be made from clay. Bricks are commonly used as a replacement material for existing sidewalks initially constructed of bricks or pavers. Conversely, bricks or pavers are not used even as a temporary replacement material when concrete or asphalt sidewalks are being repaired. Often bricks and pavers can be salvaged and replaced and this is a common spot maintenance practice for brick and paver sidewalks. Occasionally asphalt is used to temporarily fill a gap, but this is not considered a permanent solution.
Most suitable:	Bricks and pavers are used in certain environments for their aesthetic appeal. The best repair for minor displacement of one to a few bricks or pavers is to replace or reset them. This is one of the major benefits cited for brick and paver maintenance. The grade will have to be adjusted before the material is replaced. This is often more challenging than it sounds for tightly placed bricks and pavers since they are difficult to completely extract and even more difficult to replace.
Least suitable:	Spot replacement and adjustment of bricks and pavers is not feasible when the underlying grade is impacted by tree roots. Deformation forces can also impact large segments of brick or paver sidewalks necessitating a larger scale repair.
Durability:	Repairs done appropriately and expertly can be considered permanent fixes, but are very dependent on the stability of the subgrade and avoidance of tree roots.
Characteristics:	Bricks and pavers are replaced or reset. Temporary measures can include asphalt ramps and wedges.
Recommendations:	The replacement of bricks and pavers is strongly recommended when they become a tripping hazard. When tripping hazards are reported, the community may respond with a temporary fix such as an asphalt wedge or a patch if the brick or paver is extracted or missing. When bricks and pavers have to be replaced, the subsurface should be regraded. In other situations, vegetation may need to be properly controlled. Tree roots will often lift bricks and pavers. The preparation of an adequate base course is one of the most important aspects of installing and replacing bricks and pavers and future maintenance needs can be reduced with keen attention to this construction detail. Repair of bricks and pavers – even the small maintenance tasks – require experienced workers. It is not recommended that untrained laborers begin making these types of repairs without proper training.
Technique:	Small spot repairs can be made by resetting the material in place. This is advantageous for repairing tripping hazards. Larger areas can also be replaced, but the effort becomes much more involved. However, the larger the effort becomes, the easier it is to address sub-base issues. Another temporary measure is the use of asphalt as a patch or wedge.

5.2.8 Repairs to Curb Ramps

Curb ramps are required to be in place at every intersection where an accessible route crosses a curb to allow access to crosswalks for people with ambulatory disabilities. Once ramps are in place, their maintenance is critical to enabling accessibility. This section discusses ramp repairs while Section 5.3 provides guidance on seasonal maintenance of ramps.

Curb ramps should meet the same general thresholds for repair as sidewalks. Complicating the need for repairs for ramps are tight tolerances for running grade and cross-slope (see Section 4). Curb ramps built to the maximum slopes can easily fall out of compliance with just a slight displacement. The repair methods for sidewalks are all applicable to curb ramps – patching, crack-filling, wedging, mud-jacking, grinding/cutting, and replacement.

The other unique feature of curb ramps that separate them from sidewalks is the detectable warning surface, which is used to alert people with visual disabilities that they are about to enter a vehicular way as they descend into an intersection. Truncated domes are currently the only acceptable form of detectable warning that should be used for curb ramps. Detectable warning devices of the past and present often entail special repair solutions. Depending on the initial type of detectable warning device put in place, further annual maintenance may be necessary. In many parts of the U.S. where the truncated dome panel will not be subjected to plow blades or inclement winter weather, a viable short term repair for the panel is to fasten or re-fasten them with glue or screws. This can be done with little effort and may hold up until the ramp is reconstructed.

Material:	Replacement material for ramps is concrete with truncated domes as the detectable warning field. Occasionally the ramp may have a brick or paver border
Most suitable:	Ramp replacement is the best and longest term repair solution for curb ramps. Although temporary repairs are often necessary, only ramp replacement ensures the best method of installing appropriate grades for the ramp. It also allows for the inclusion of the latest forms of detectable warning fields.
Least suitable:	When simple repairs, such as grinding and horizontal cutting, can result in significantly elongating the life of the ramp and the current detectable warning is in place and considered effective.
Durability:	Replacement of curb ramps can be considered permanent fixes.
Characteristics:	Ramp is removed and replaced with a new concrete ramp.
Recommendations:	Given the need to create a very predictable and workable transition between a sidewalk and a street crossing, replacing problem curb ramps with new replacement ramps is often the best long-term solution. This may involve replacing the level landing and a few adjacent sidewalk panels to bring the ramp into ADA compliance.
Technique:	The damaged ramps are removed either by hand or a skid-steer loader after they are broken up. A heavy piece of equipment that makes use of a strong, telescoping boom attached to a digging bucket can also lift individual ramps from the grade. Steel or wooden forms are pinned in place. The existing grade is adjusted and in some cases additional fill is used to level the grade. The base surface is mechanically tamped if fill is added. Concrete is poured into the grade between the two forms and the remaining pieces of concrete (back of gutter and the level landing). A strike-off board is used to level the concrete as the void is filled where the old ramp existed. Finishers often insert pre-manufactured truncated domes into the fresh concrete and finish it in place or use specially made forms to press in the domes (this method has created widely questionable results). Finishers will trowel the surface of the concrete to push the aggregate from the surface and to move more of the mortar or "slurry" to the top. This provides for a smooth finish and aids in the final step of finishing which entails the use of a broom to finish the concrete with light brush marks made perpendicular to the direction of pedestrian travel down and up the ramp.

5.2.9 New Materials

Figure 30: Porous pavement in Washington
D.C. Photo by Melissa Anderson

Pavers made from recycled rubber and plastic have been in use in the public right-of-way since the year 2000. They can be used as a substitute for traditional sidewalk pavements. These pavers are modular systems similar to large concrete pavers and have uniform and tight fitting joints which are more comfortable for pedestrians. Some are linked together with tabs and are pinned in place. They have no known unique maintenance requirements. They are swept and cleaned like conventional concrete sidewalks.

As a maintenance measure, some communities have been attracted to these pavers for applications around trees where tree roots have caused concrete sidewalks to heave. They are half the depth of concrete sidewalks and can be cut to fit around trees. They are typically more expensive than concrete in most applications. One of the additional maintenance benefits is that they can be reset just like other pavers. If they begin to pitch because of tree roots or sub-base problems, the base can re-graded or the tree roots trimmed and the pavers reset. Additionally, if a panel needs to be replaced a new one can be clipped and pinned into place. Manufacturers of these products have detailed specifications and directions on how the base course should be prepared for the pavers and how the pavers should be installed. Since these are relatively new, it is not known what their true life is, but the main manufacturer is providing a range of limited warranties from 5 to 25 years on these products.

Other recently introduced products include those that increase permeability of walkways. This includes both porous concrete and asphalt and assorted pavers products that are either porous themselves or divert water to gaps in the pavers. They have unique maintenance requirements such as annual vacuuming to clean out the voids in the material that can be filled with fine material such as silt or sand. Some these new surfacing types have special significance for sidewalks especially around trees because they will often maintain their flexibility around roots and allow excellent water infiltration to feed roots. These pavement types will be covered in more detail in Chapter 6 on new construction practices to reduce maintenance.

5.3 Maintenance of Crosswalks

Marked crosswalks indicate locations for pedestrians to cross and signify to motorists where they need to yield to them. Crosswalk markings are often installed at signalized intersections and other selected locations. It is critical that crosswalks be visible to motorists, particularly at night. Ladder or continental crossings using wide strips of retro-reflective material are the most visible. This also places a greater maintenance responsibility on agencies in charge of maintaining crosswalks.

The focus of this section is on the maintenance of crosswalk markings; however, it is important to note that maintenance should include the actual street surface where crosswalks are located, and not just the pavement markings. Crosswalks represent the accessible path within the street and require a higher level of maintenance than the surrounding roadway because pedestrians are less tolerant of defects than motorists. A minor pothole may not present an issue for most motorists, but can present a significant issue for pedestrians. Surface defects in crosswalks should be noted when crosswalks are inspected or re-marked, and repairs should be completed quickly.

5.3.1 Crosswalk Marking Material

Agencies use a number of different materials for marking crosswalks, including paint (water- or oil-based), epoxy, polyurea, thermoplastic and pre-formed marking tape. Often these marking materials are divided into two categories with paint being considered non-durable and all other markings considered durable. Transportation agencies weigh several factors when determining which marking material is most appropriate including costs, durability, retroreflectivity, friction coefficient (avoiding slip hazards) and whether or not the material can be applied using existing agency labor and equipment. Most communities contacted for this guide use thermoplastic, which is recommended for its longevity. Many also frequently use paint, particularly on existing roads or when there is an immediate need. Epoxy was also mentioned by a number of communities. Thermoplastic and epoxy markings are used most often on repaving projects. Those communities that use paint markings typically use city crews and equipment to do the work while they commonly use contractors to install thermoplastic markings.

The primary maintenance problem with crosswalk markings is durability. Often painted crosswalks have to be re-striped several times a year based on the volume of traffic and the severity of the weather. The other marking materials are far more durable, but are much more expensive. In cold weather climates where the roads are salted and sanded, the abrasiveness of these materials will cause more rapid deterioration of the markings. Agencies researched for this guide also said snowplows often damage thermoplastic markings. Several agencies have recessed thermoplastic markings to decrease the likelihood of snowplow damage, but this is very expensive.

Another durability-related maintenance problem is the conspicuity or retroreflectivity of the markings. A large percentage of pedestrian fatalities occur in the evening when conspicuity is reduced. Crosswalk markings must retain their retroreflectivity, usually accomplished by adding beads or other retroreflective material to marking material. But when the markings wear, the retroreflective quality of the material is often lost first. This guide recommends that agencies use the methods as established in the MUTCD and described on this website to check for the proper retroreflectivity of crosswalks:

http://safety.fhwa.dot.gov/roadway_dept/night_visib/pavementreg.cfm.

A problem with thermoplastic markings and some pre-formed marking tapes is that they sometimes become more slippery with wear. Manufacturers of these materials have taken steps to significantly improve the friction factor of their materials, but slippery markings make it necessary to replace the markings sooner. Successful use of pre-formed thermoplastic also relies on applying the material to a dry, clean surface nearly completely devoid of existing crosswalk material. This can complicate applications on existing pavement.

Epoxy markings involve a two-part system using a simple mixture of two bonding components. The most significant downside is that its application requires specialized equipment with a complex process control system which is required to assure proper blending of the two components. In some states, only a handful of private vendors have the equipment necessary for this application. Sandblasting of the pavement is normally required to remove existing materials and some epoxies have a relatively long cure time (up to 45 minutes depending on ambient conditions).

Figure 31: Relative comparison of crosswalk marking materials

Material	Relative Cost $=Low $$$$=High	Lifespan (months)	Retroreflectivity *=Low ***=High
Paint	$	3 – 24	*
Epoxy Paint	$$	24-48	**
Thermoplastic (sprayed)	$$$	48-72*	**
Pre-formed Tape	$$$$	36-96*	***

Note: Estimates based on minimum standard crosswalk treatment and updated to reflect 2013 comparative costs.^16,17 Thermoplastic and tape have shortened lifespans in snowy areas where they are often damaged by snowplows. Inlaid thermoplastic or pre-formed tape may last significantly longer than standard surface applications.

Figure 31 displays characteristics of four common crosswalk marking materials. It should be noted that costs vary widely across the country and the ranges provided are approximate. Similarly, material lifespans are strongly impacted by the volume of traffic passing over the marking, and the use of snowplows on streets. Depending on the crosswalk marking material used, snowplows can snag or cut into markings.

This guide includes a number of broad recommendations for marking crosswalks, however, there are considerations that will affect those recommendations which are summarized in the next section.

• To promote a longer lifespan when using paint, a "high build grade" is recommended with glass beads for retroreflectivity. High build uses an acrylic cross-linking emulsion that allows for applications of up to 20 mils.
• According to the national Bicycle and Pedestrian Information Center, the most durable, and recommended, crosswalk marking material for new pavements is inlay tape. It is highly retroreflective, long-lasting, slip-resistant and requires little to no maintenance. Although initially more costly than paint, both inlay tape (preformed tape) and thermoplastic are more cost-effective in the long run. Inlay tape is recommended for new and resurfaced pavement while thermoplastic may be a better option on rougher pavement surfaces. Both inlay tape and thermoplastic are more visible and less slippery than paint when wet.
• Use a long-lasting marking for crosswalks at the time of new construction, reconstruction, or repaving using funding from the construction budget for the project.

5.3.2 Crosswalk Marking Considerations

Life-Cycle Costs

Figure 32: Old crosswalk markings removed
for new crosswalk marking tape.

Unit costs for crosswalk marking materials vary considerably across the country. But given the durability issues discussed above, life-cycle costs are an essential consideration. A National Cooperative Highway Research Program (NCHRP) Synthesis 306: Long-Term Pavement Marking Practices provides cost comparisons and a life-cycle cost table. In general, thermoplastics provide a life of two to three times that of paint for long lines, however, costs averaged almost five times that of paint (epoxy markings had a life of two to three times that of paint, but had a cost of four times that of paint). Thus, when life-cycle cost was calculated, paint was half the cost of thermoplastic. It is important to note that costs and durability ranged significantly in this study. There is a clear trade-off between the durability of thermoplastic and the lower cost of paint. Communities that use paint to mark crosswalks indicated that they must repaint crosswalks two to three times per year, whereas thermoplastic markings typically last 2 to 3 years.

Agencies should perform life-cycle cost analysis for different materials based on their local product costs, labor costs, the cost of diverting traffic, and real-world observations of product lifespans, given local maintenance conditions. The following factors will also affect such a local analysis.

Traffic

Traffic has a significant impact on the longevity of crosswalk markings. Also, frequently repainting crosswalks in high-traffic areas incurs traffic control costs that agencies should take into account as an important cost factor. Products that may be more expensive up front may be less expensive over time if they need to be replaced less frequently.

Communities can minimize the impact of traffic by spacing the bars of a crosswalk ladder design or a continental design so that the wheel wear occurs between the bars. Since turning vehicles can significantly increase degradation of pavement markings, locating markings out of turning areas, when possible, can reduce maintenance. However, this should never be done when it will compromise the appropriate placement of a crosswalk, thus this recommendation may have limited applicability at most intersections.

Equipment and Labor

Costs will be dramatically affected by the availability of equipment and labor. For instance, if thermoplastic equipment has already been purchased by an agency and in-house labor is trained and available for crosswalk marking, costs will be minimized. For communities that want to avoid investment in such equipment, some applications of markings are relatively inexpensive, such as applying tapes (cold or heated). Another equipment issue is whether a community commonly uses snowplows. Thermoplastic and pre-formed tape may not be appropriate in areas using snowplows unless the markings are inlaid in the pavement, which makes it less likely that a plow blade will pull the material off the street.

Pavement Type and Previous Markings

When considering the type of crosswalk marking material, pavement type – asphalt or concrete – is a consideration along with the type of material that was previously used as the marking material if an agency is simply remarking the crosswalk.

One of the benefits of restriping with paint is that the new paint can sprayed on top of the old paint after the surface is cleaned and any paint flaking is removed. Liquid thermoplastics can generally be placed over worn paint or liquid-applied thermoplastic markings. However, liquid thermoplastics cannot be easily applied over tapes unless at least 70 to 90% of the former marking material has removed through grinding or sand blasting. Similarly, tapes cannot be reapplied over existing tapes unless a minimum of 80 to 95% of the former tape has been removed through grinding or sand blasting. The performance of marking material is significantly affected by application over existing materials; it is important that agencies talk to vendors about this issue.

In new applications on asphalt surfaces, agencies typically use inlay tapes, hot-applied thermoplastics or high build grade applications of paint-based markings in order for the markings to be visible. Markings generally last longer on asphalt than concrete, especially for a relatively new surface. Tapes can also be rolled in when new asphalt is being rolled; this is generally a very good way of improving the durability of the tapes during the winter and plowing applications. For new concrete surfaces marking applications are somewhat more limited and preparation of the surface is even more important than asphalt. Grooving concrete for inlay tapes is very expensive, but provides superior durability during the winter months where snowplows are in use.

Many agencies use more expensive inlay markings on new street, reconstruction, and repaving projects when these materials are covered by construction budgets. But the cost of remarking crosswalks usually comes out of the maintenance budget, which may not allow for easy reapplication using the same materials.

Maintenance budgets tend to be tight, whereas including more expensive marking materials in a construction project, represents just a small part of a larger project budget. Importantly, some applications of more expensive tapes can only be applied initially at the time of resurfacing or reconstruction.

Although there is a certain economy of scale and simplicity for agencies to use one marking type for initial marking and another for remarking, it is more important to make decisions about remarking independently of the original application. Traffic volumes, pavement surfacing type, initial marking material that will be marked over, cost, and availability of application equipment will be factors in the how agencies will need to consider a mix of treatments for remarking crosswalks. Agencies will need to be flexible in their approaches to remarking crosswalks. For example, it may be cost effective to use paint for remarking of a crosswalk on a lower volume street, while expensive pre-formed thermoplastic material will be used for other crosswalks in a higher volume downtown location even when the old material has to be ground off for re-application.

5.4 Maintenance of Pedestrian Signals

5.4.1 Background

Based on the research conducted for this guide, agencies considered their pedestrian signals to be durable with the most serious maintenance problems related to signal "take-downs" due to vehicle crashes. This is in contrast to the perception of many pedestrians who often say they find pedestrian signals more temperamental. Other significant problems reported by communities requiring maintenance include malfunctioning push buttons and signal heads.

Another set of hardware problems relates to the controller for the signal system. The controller itself is the device that manages the entire signal system for the intersection, but occasionally problems with the controller will cause pedestrian signal malfunctioning requiring a maintenance call.

5.4.2 Maintenance Recommendations for Pedestrian Signals

Timely Response

Agencies should have multiple means for members of the public to report malfunctioning signals and have a system in place for a quick response. A malfunctioning signal can be a serious hazard for pedestrians, and people should be strongly encouraged to report malfunctions. In the research conducted for this guide, response times for agencies for repairs ranged from several hours to two weeks with the majority of communities reporting that they have signals fixed within one to two days. Agencies should establish a protocol that results in a response between 24 to 48 hours after the report is received (in high pedestrian and traffic volume areas perhaps even sooner). This will result in the reduction of hazards and an improvement in signal maintenance.

Inspection

If a community has a sidewalk inspection program, push button signal actuators should be inspected for functionality at the same time that adjacent sidewalks are inspected. Pedestrian signals should also be inspected at the same time as vehicular signal heads at the same intersection. Almost all communities that were contacted for this guide indicated that they have had few issues with their pedestrian signals, although some indicated they have some issues with pushbuttons for the signals. In discussions with pedestrians and pedestrian groups, their perspective was different as they often reported pushbuttons that seem to be malfunctioning. In some cases, pushbuttons have a propensity to stick as they wear. For inspection, these are conditions that should be monitored:

• Cracked or broken pushbutton hardware
• Pedestrian signal heads or push buttons that are turned askew
• LEDs in pedestrian signal heads that are fading in conspicuity
• Vegetation obscuring pushbuttons or pedestrian signal heads

Inspection processes provide a perfect opportunity to check button mounting locations and how current accessibility standards are being maintained. Although more of an operations issue, agencies should remember to change signal timings for pedestrian signals when they change cycle length timings as part of intersection signalization updates and upgrades. Inspection regimes may need to be changed with the installation of Accessible Pedestrian Signals (see below).

Accessible Pedestrian Signals

Accessible Pedestrian Signals may be required for all pedestrian signal systems as the PROWAG become finalized into law. Agencies will need to take seriously their responsibilities for these new signal adaptations and take steps to ensure proper operation and maintenance. Fortunately, APS devices work with existing traffic signal controllers and usually require no additions to equipment in the signal controller cabinet for installation and operation. The NCHRP report Accessible Pedestrian Signals: A Guide to Best Practices indicates that agencies will have to monitor these new devices for malfunctions relating to WALK indication, locator tone, and signal interaction which may fail to work correctly, to avoid dangerous crossings for pedestrians with vision impairments. The overseeing agency should conduct an audit or checkup of APS installations on a regular basis, and more frequently if the weather is harsh. At a minimum, APS should be inspected every 6 months, after repairs to the intersection signals, poles or controller, and after changes to signal timing.

Occasionally an agency may receive a complaint that a locator tone on an APS is too loud or needs maintenance. The volume of the tones and messages can be adjusted and should only be audible 6-10 feet from the signal pole. The volume adjusts according to ambient noises, but if the environment around the pole changes significantly, the volume settings may need adjusting. Pushbutton manufacturers should be contacted with questions or ongoing problems.

Newer technologies – most associated with APS – will improve the day-to-day performance of pedestrian signals. It is recommended that agencies become acquainted with these technologies by surveying new devices offered by many vendors.

LED Technology

The replacement of signal heads with LEDs has significantly reduced the need for replacement of light fixtures in signal heads and has been the single most maintenance-reducing improvement related to pedestrian signals in the past 10 years. LED lights last for approximately 100,000 hours, many times the life of incandescent bulbs.

However, there are new maintenance considerations with LED lights. First, LEDs generate so little heat that they do not melt off accumulated snow and/or ice as readily as incandescent systems. Second, because LEDs last much longer than incandescent bulbs, regular lens cleaning and LED fading may become an issue. The frequently asked questions on the MUTCD website address this issue:

"Agencies using LED-based signals should be aware that these signals need to be monitored for adequate brightness of the signals and for needed replacement, typically well before the signals fail totally. LEDs have a long life before total failure, but the LEDs gradually become dimmer over time and may become so dim that they cannot be adequately seen under all lighting conditions. This is in contrast to signals using incandescent bulbs, which usually remain sufficiently bright over their full lifetime and then fail completely by "burning out". Agencies thus quickly become aware of and replace failed incandescent signals. Agencies need a different strategy for monitoring and replacing LED signals."¹⁸

There are reasons from a maintenance perspective that agencies would want to consider the use of LED technology in traffic signals.

5.5 Maintenance of Pedestrian Signage

Wear and tear on signs results in discoloration and loss of retroreflectivity. Signs that act as wayfinding devices for pedestrians are no exception to this on-going maintenance problem. Unlike markings, signs have a much longer life – quite often more than 10 years. Several factors tend to lessen the life of signs – ultraviolet radiation and airborne pollutants can dramatically degrade a sign's useful life. Vandalism is also a significant maintenance problem for signs in general. Sign replacement for pedestrian-related signs (wayfinding, street signs, etc.) tends to take a lower priority to the maintenance of signs for regulatory and warning purposes, such as stop and yield signs. Regulatory and warning signs also communicate messages to non-vehicular users and regulate movements at intersections of paths and sidewalks with streets.

According to the MUTCD, maintenance activities should consider proper position, cleanliness, legibility, and daytime and nighttime visibility. The MUTCD requires signs to be conspicuous and legible. Agencies should anticipate costs associated with keeping signs well maintained. At the same time, any changes required by the MUTCD can be incorporated. To assure adequate maintenance of pedestrian signs the following actions should be taken:

• Scheduled inspections. These should occur during daylight hours, but also during nighttime hours to check retroreflectivity.
• Clean signs. This includes power washing signs to maintain their visibility.
• Enlist help from other public employees. Employees of the agency including law enforcement, public works, highway department, etc. who are traveling the roadways should be encouraged to report any damaged, deteriorated, or obscured signs at the first opportunity.
• Replace signs. Signs have a life of about 10 years and need to be replaced on that cycle or close to that cycle. Damaged or vandalized signs also need to be replaced.
• Vegetation removal. Trees, bushes, and weeds need to be removed or trimmed so they do not block the visibility of signs.

Retroreflectivity is one of the most important aspects for sign maintenance and is covered in depth in the MUTCD. It requires agencies to use an assessment or management method that is designed to maintain sign retroreflectivity at or above minimum levels cited in the MUTCD (Section 2A.08 Maintaining Minimum Retroreflectivity). Five assessment or management methods are recommended in Paragraph 4 of Section 2A.08 in the MUTCD for possible use. The MUTCD minimum retroreflectivity standards cover many pedestrian signs, but some sign types can be excluded from this requirement including path signs that are intended for exclusive use by bicyclists or pedestrians. Another good resource for information on retroreflectivity can be found at the FHWA Sign Retroreflectivity Toolkit at:

http://safety.fhwa.dot.gov/roadway_dept/night_visib/retrotoolkit/requirements/.

5.6 Seasonal Maintenance

Section 5.2 through 5.5 covered the maintenance techniques and approaches necessary to tend to the wear and tear on sidewalks, crosswalks, signals and signs. However, most people associate maintenance of pedestrian facilities with clearing snow and debris that blocks such facilities. This means sweeping, vegetation removal and control, and snow and ice removal. This connection to maintenance is ever apparent to property owners living adjacent to sidewalks because most state laws and/or municipal ordinances make this day-to-day maintenance their responsibility. This section will discuss the most common types of everyday maintenance and the techniques that are used.

5.6.1 Vegetation Removal and Control

Street trees and other plants adjacent to the sidewalk are a beneficial street amenity for a variety of reasons, including provision of shade, carbon dioxide reduction, increased property value, stormwater control and visual interest. Trees are considered by communities as one of their most important assets in the street right-of-way. However, vegetative growth encroaching upon sidewalks or paths is a serious condition that requires maintenance. Sightlines to driveways and intersections must also be maintained for pedestrian safety. In addition, the surface of the sidewalk must be kept free of vegetative debris. Many communities require adjacent property owners to keep a sidewalk free of vegetation or property owners are doing so on their own without any prodding. The main problems associated with vegetation are identified in Section 3.2.2.

Recommended Practices

Vegetation within the public right-of-way is managed in a variety of ways. Some communities require adjacent property owners to maintain vegetation planted between the sidewalk and the curb. Other jurisdictions require property owners to obtain a permit in order to plant anything other than grass between the sidewalk and the curb so that proper sightlines and the pedestrian clear zone are maintained. Many communities employ arborists who provide expert assistance on inspection and trimming of trees which will help in the maintenance of this planting strip.

While many communities, especially moderate to large sized cities, have ordinances regarding the maintenance of vegetation, they are often not very well enforced or there is poor reporting of problems. It is strongly recommended that municipalities enforce those ordinances to maintain vegetation along the sidewalk on private property and in the public right-of-way. For those communities lacking an ordinance, it may be difficult to find support for efforts to manage vegetation near sidewalks and paths; thus, the passage of an ordinance is a recommended first step. There are several demonstrated techniques to control vegetation: edging, limb trimming, vegetation debris management, and vegetative planting.

Edging

Certain types of grasses or a combination of grass and soil will build up on the outer edges of the sidewalk. Edging is a technique that cuts back the vegetation to the outside limits of the sidewalk. Edgers are both motor powered and hand powered. A wheel rests on the sidewalk as the devices are used on the edges of the pavement. These machines are capable of trimming the vegetation all the way back to the edge of the sidewalk and are especially effective if this task is done routinely. Vegetative build-up on sidewalk edges is often an under-identified problem, but can result in serious issues on narrow sidewalks or where drainage is affected.

Limb Trimming

Branches can quickly grow into the pedestrian accessible route of a sidewalk or path. According to accessibility guidelines, objects protruding more than four inches into the pedestrian circulation path must be at least 80 inches above the surface of the walkway. Objects closer than that must be trimmed back. A variety of tools can be used to trim branches such as long handled pruners, pruning shears and saws. The AASHTO guide for bicycle facilities should also be consulted for shared-use paths. The minimum vertical clearance for paths is 92 inches.

Vegetation Material Management

The most important task related to cleaning up vegetation is the removal and collection of leaves in the fall. Leaves can lead to very slippery conditions when wet and they can easily cover up tripping hazards. Communities and property owners rely on the obvious tools to maintain sidewalks including rakes and leaf blowers. Agencies often have specially equipped trucks with baskets to collect piled leaves.

5.6.2 Sweeping

While most communities sweep streets free of debris, very few have an active citywide, sidewalk-sweeping program. It is much more common to have communities support sidewalk sweeping through business improvement districts aimed at downtowns and commercial business districts. For example, the City of Perry, GA, sweeps sidewalks in the core business district three times per year. On State Street in Madison, WI, it is done weekly. The City of Concord, NH, sweeps sidewalks citywide every spring. In the absence of a coordinated citywide or Business Improvement District approach to sweeping, adjacent property owners more commonly perform this work and are often required to by a community ordinance.

The typical tools for sweeping sidewalks depend on the scale of the effort. Communities will often use a power driven rotating broom mounted on a tractor or skid-steer loader if sidewalks are swept clean on an area or community-wide basis. Although this tends to be a fast way to clear the sidewalk, the swept material is very difficult to control and is usually just simply pushed to another location. This option may be preferred if the material, such as soil or sand, is simply being returned to a tree buffer where it was initially situated.

Small scale efforts include using leaf blowers to corral dirt and refuse into a pile or windrow to be swept up later. A simple broom is the tool of choice for adjacent property owners who occasionally need to sweep a messy sidewalk.

There are several conditions that communities must pay special attention to when considering sweeping needs. Curb ramps and low sections of sidewalks or multi-use paths where water settles provide conditions for dirt to settle as well. When still wet, the silt that remains is extremely slippery. Secondly, paths must be closely observed for sweeping needs or swept on a weekly or bi- weekly basis. Paths are sometimes plagued with broken glass which is especially troublesome for bicyclists' tires. Given the unpredictable nature of debris or refuse left on paths, relying on reports from users is often a viable maintenance approach, assuming communities respond quickly to reports.

5.6.3 Snow and Ice Removal

Following a snowfall, snow and ice must be cleared from sidewalks, curb ramps and crosswalks promptly to provide safe and accessible passage for pedestrians. Common challenges to pedestrian travel after snowfall include street plowing that pushes snow onto sidewalks or blocks crosswalks, clogged or obstructed drains that create puddles at curb ramps, patches of ice that create slip hazards, and stretches of snow and ice covering sidewalks. Jurisdictions should have policy and action plans that address these key issues.

While the proposed ADA Guidelines for the Public Rights-of-Ways specify that sidewalks have 48 inches of clear passageway, different municipal ordinances have varying degrees of detail for how best to achieve a safe clear zone for pedestrians after a snowfall. For example, some ordinances require clear widths for snow removal. Other ordinances allow the use of aids such as sand, ash or salt on ice to prevent slip hazards while others require the breaking out of ice. Some ordinances specify the maximum allowable height of snow banks and forbidden zones for snow piles, to maintain proper visibility of pedestrians. Some jurisdictions require snow removal from specific features such as fire hydrants, benches, driveways and curb ramps.

In the event of a snowfall, communities need to make streets and sidewalks passable to pedestrians. Removing snow and ice should be thought of as a community responsibility that covers the entire public right-of-way. And since sidewalks are part of the public right of way, efforts to remove snow and ice need to occur in a reasonable time period following a snowfall. Elements of an effective snow and ice removal program include: timeframe for removal, responsibility for removal, ordinances, compliance efforts, and planning and outreach strategies.

Timeframe

Removing snow and ice within a 24 to 48 hour period following the culmination of a snowfall is considered a reasonable timeframe for removal. In regions where snowfall is infrequent and the climate is very temperate, many communities rely on a quick melting method or a "melt strategy" for responding to most of their snowfalls. Rather than remove snow and ice, a community may rely on warmer temperatures shortly after a storm to melt snow and ice before mobility becomes an issue. Although this may be a reasonable approach for light snowfalls or those that occur in relatively warm weather, communities still need to have a contingency plan in place (or have it clearly covered in an ordinance) to deal with snow and ice that remains longer than the 24 – 48 hour time period. Snow that falls in the coldest and darkest months will have a much greater tendency to stay frozen (or thaw and freeze) and presents more problems compared to snowfalls in November, March, and April.

In parts of the country where snowfall is more frequent, communities will need to be prepared to respond to all snowfalls. Expecting snow to melt without impacting pedestrian travel is not realistic. It is also common and appropriate to require a shorter timeframe to respond to snowfalls in high pedestrian zones such as in business districts, around college campuses, school areas, and where pedestrians need to access transit. Rather than establish a time period for removal (i.e., 24 to 48 hours after snowfall culmination) another strategy is to set a specific time for when all snow must be cleared. For instance, a time of day can be set. Ann Arbor, MI, requires that any snowfall accumulation before 6 AM must be removed by noon while Alexandria, VA, requires different timeframes depending on the category of storm. The larger the storm the more time allotted for snow removal. All of these are responsible and recommended approaches for responding to snowfalls. All timeframes must balance the needs of pedestrians and provide a reasonable amount of time for the agency and property owners to remove snow.

Responsibilities, Laws and Ordinances

Sidewalks are the most common pedestrian facility, and although the removal of snow and ice from them is considered to be a very important safety issue, removal of accumulations from curb ramps, crossings in medians islands, and transit stops are equally important. A failure to remove snow from one of these facilities can easily disrupt or even stop a pedestrian trip from occurring. Similar to the maintenance of sidewalks, curb ramps and median crossings are potential problem areas that have to be addressed by communities through ordinances and public snow removal practices.

A common practice is to require by ordinance that residential and commercial property owners remove snow and ice from sidewalks that abut their property within a specific time frame and often that will include adjacent curb ramps. This allows city crews to focus on priority locations for snow removal such as in business districts, school zones, transit stops, bridges, median crossings, along property it owns, and other priority locations. Because the majority of sidewalks abut private property, and most communities rely on property owners to remove snow and ice, the success of sidewalk snow removal relies on a coordinated program for education and enforcement of the community. Strong and efficient enforcement is also instrumental for compliance to snow removal ordinances. Within ordinances, there are varying degrees of requirements, guidance, inspection and enforcement provisions to ensure that sidewalks are cleared. The ADA now requires pedestrian facilities to be cleared of snow and allows only temporary closures. The most comprehensive programs, and those recommended by this guide, specify requirements such as removing snow and ice from curb ramps and crosswalks as well as sidewalks.

Most snow removal practices are established by local ordinances. State laws typically enable communities to establish ordinances covering maintenance practices for sidewalks or for the entire street right-of-way including sidewalks. In other cases, state law or established case law may establish the responsibility for snow clearance at the state level. Communities are encouraged to become knowledgeable regarding relevant state laws and be especially aware of local ordinances addressing sidewalk maintenance. For instance, the State of New Hampshire requires state and local jurisdictions to perform all sidewalk related construction and maintenance activities including snow and ice removal at no cost to the adjacent property owner.¹⁹ This places the responsibility for clearing all snow and ice from sidewalks on municipalities. The state law grants municipalities the flexibility to determine a course of action, such as a snow removal action plan, for prioritizing snow removal activities within a reasonable amount of time. As a result, communities in New Hampshire are encouraged to have a snow removal plan that outlines the requirements of "reasonable removal of snow, ice and debris."

There are several additional factors that tend to negatively impact the success of snow removal by adjacent property owners and need special attention: the presence of rental properties, especially in areas near colleges or universities, and the presence of elderly or disabled households that require assistance to remove snow. Factors that tend to positively impact snow removal are enforcement mechanisms and the ability of communities to respond in a timely fashion to non-compliance with ordinances. In smaller communities, it is common for neighbors to informally help each other remove snow, where larger communities tend to develop snow removal assistance programs.

Having adjacent property owners assume responsibility for clearing sidewalks is a common and economically efficient (for the community) technique for snow removal as long as abutting owners are informed and held responsible for removal. Furthermore, the community must be prepared to step in to remove snow and ice when property owners fail to do so, as well as remove snow from intersections and its own sidewalk and path property. Although this is a time-honored practice, it has been called into question on equity grounds. Arguments have been directed at this approach because it taps the resources of adjacent property owners for maintaining sidewalks when the street itself (in the same public right-of-way) is maintained by the community. While communities remove snow and ice from adjacent streets using general fund or transportation fund dollars, adjacent property owners with sidewalks are responsible for removal using their own resources. Property owners who do not have sidewalks have no such responsibility or burden yet benefit from the use of cleared sidewalks in the parts of the community that do have sidewalks.

Jurisdictions that take on the full responsibility of snow removal from sidewalks will assume increased levels of efforts or cost in exchange for more consistent and potentially convenient snow removal programs. When communities take on snow removal they can do so with relatively few pieces of equipment in contrast to every property owner with sidewalks having to respond to snowfalls with their own equipment. There are several measures that will streamline the process: having appropriate equipment for removal, parking restrictions to expedite simultaneous plowing of streets and sidewalks (when sidewalks are immediately adjacent to the parking lane or agencies need to remove snow from buffer zones in commercial areas) and the use of performance based contracts to balance the costs of annual sidewalk snow removal when contractors are used. Some of the additional benefits to communities in providing community-wide snow and ice removal are: increased confidence among pedestrians who can expect uniform level of service (having just a couple of property owners not remove snow and ice can significantly disrupt a trip), curb ramps and medians can also be cleared at the same time, and agencies can anticipate and inform constituents of clearance completion schedules helping residents with their own trip and transit planning.

When property owners are required to remove snow from abutting properties, communities will still have the responsibility to remove snow from sidewalks adjacent to public lands. This should be a shared responsibility between the jurisdiction, county, state, transit and private agencies and institutions. Responsibility can often be a point of confusion that may lead to uncleared sidewalks. Clearly defined responsibilities are important to a successful snow removal program. Many communities deploy crews or hire contractors to clear snow and ice from sidewalks adjacent to public lands or buildings. Often this is a shared responsibility between Parks Departments and Public Works Departments. Some smaller communities require school, fire and police staff to clear snow from sidewalks around buildings. A snow removal plan that outlines clear responsibilities and assigns those responsibilities through written agreements are important when coordination is required between agencies, institutions and organizations.

Prioritization

Very few communities have a prioritized system for sidewalks to be cleared of snow and ice by city crews, but it is a recommended practice. Either as part of or after streets are plowed, many communities will focus attention on clearing sidewalks near schools, transit stops and business districts. This scheme of establishing priority routes for clearing sidewalks can function when communities themselves are solely responsible for the clearing of snow from pedestrian facilities or when adjacent property owners are responsible. For the latter, the community would ensure that all sidewalks are suitably cleared of snow and ice and if they are not the community's crew would clear the sidewalks and charge the adjacent property owner. The City of Alexandria, VA, prioritizes sidewalks in the following order: 1) schools, 2) high transit use areas, 3) city facilities and 4) bus stops.

Yet another positive development over the past 20 years is the creation of Business Improvement Districts (BIDs) and Special Improvement Districts (SIDs) and the ability to use these districts to provide basic maintenance of walkways including snow and ice removal. Businesses are responsible for a special tax that among other things, funds maintenance activities such as snow and ice removal from sidewalks by a hired contractor. This is also a clever way for communities in low snowfall areas to ensure removal of snow from sidewalks in the busiest pedestrian areas.

Compliance Efforts

For those communities that require property owners to remove snow and ice from walkways, proper and prompt enforcement is the key to a successful snow removal program. Most communities are granted the power to fine property owners or charge them the cost to remove snow and ice from their sidewalks if they fail to do so themselves. Although it may seem like a callous action, using fines or charges is a recommended approach.

Communities that combine education efforts with strict enforcement of snow removal are more successful at having snow removed from walkways by adjoining property owners. Communities can use police, public works staff, and inspectors to issue citations to non-compliant properties. Typically, a public works employee or inspector is the most sensible choice. Communities will often have a code enforcement person who writes notices for other code violations such as property violations (grass too long, junk cars on premises, vegetation encroachment) so the same person that handles summer complaints can handle snow and ice complaints in the winter. One strategy that should be considered with apprehension is the issuance of warnings before citations. This process can elongate the time that the sidewalk remains impassable to pedestrians and creates additional work for the enforcing agency. In the end, pedestrians may be presented with longer periods with winter sidewalk hazards.

Fines can also be increased over time since residents would rather shovel snow than face increasing fines. The goal is to move toward compliance so it may be necessary to escalate fines to make this possible. A fee structure can include different fines for residential and commercial properties. Charges can accrue daily for failure to remove snow and ice and/or for the cost of crews to remove snow and ice per cubic yard. Fees collected from the fines should remain in the removal program to fund city sponsored snow removal at non-compliant properties. Recurring charges resulting in a lien on property taxes can be an effective strategy for encouraging property owners, managers and tenants to comply with snow removal requirements.

Successful enforcement programs should treat snow removal enforcement much like parking enforcement: violators are promptly ticketed, and failure to pay the initial fee results in additional penalties. Mechanisms for enforcement are performed by parking officers, police or inspectors. Like parking fines, snow removal fines can be a predictable revenue stream.

Work Plan

A snow removal plan or policy is a strategy for determining the priorities and actions a jurisdiction will take in response to a snow event. The development of an action plan is important for a successful snow removal program. Often sidewalks are a secondary priority to snow removal on streets. However, plans that address sidewalks can provide important guidance on timeliness, techniques, priorities and coordination between jurisdictions and agencies to ensure that the needs of pedestrians are met. A successful plan acknowledges that pedestrian needs are important year round. Successful action plans have the following elements relating to sidewalk snow removal policies:²⁰

• Stress the need for continuous improvements and performance measurements
• Mitigate risks and manage costs
• Utilize electronic communications and social media to enhance outreach
• Ensure compliance with federal and state laws
• Incorporate innovative and/or environmental sustainability practices that provide cost savings measures, foster efficiency of operations, and aid in efforts to preserve air and water quality
• Identify and program major snow removal equipment

Jurisdictions should include the most comprehensive information available when developing or updating a plan. It is also recommended to consider making the plan an all-season plan by including vegetation removal for sidewalks and paths. Often sidewalk ordinances include year-round maintenance provisions and the compliance efforts will be the same whether the problem is snow or vegetation. Two comprehensive guides for developing snow removal plans were reviewed for this study and are recommended in the development of a plan that specifically addresses pedestrian needs:

• The Winter Maintenance of Pedestrian Facilities in Delaware: A Guide for Local Governments outlines sources of information for winter maintenance management plans as they relate to sidewalks; provides guidance on processes for developing a plan; and highlights communities with outstanding plans for sidewalk snow removal.²¹
• Snow and Ice Control is a workbook that provides a comprehensive overview of the elements of a snow removal plan in Minnesota²²

Outreach, Problem Reporting, and Help Programs

One of the most critical ways that a community will communicate with residents after a snowfall is through a problem reporting mechanism. Residents and visitors can use an online service and a call-in number. Although this type of reporting is valuable year-round to report any pedestrian facility problem, having it available to report unshoveled walkways and impassable curb ramps and medians is absolutely essential to successful winter maintenance. Communities need to be responsive to problems including making a visit to the location to confirm the problem. Depending on the system the community has in action, the adjacent property owner is either fined or charged with removal of snow and ice from the sidewalk or curb ramp. In other cases, it may be the community itself that has failed to undertake its responsibilities for snow and ice removal. Clearing of snow and ice should occur within a 24 to 48 hour period after the report is made.

Figure 33: City of Boston fines for non-compliant snow removal

Type of Property	Failure to Remove Snow/Ice From Sidewalk	Removal of Snow/Ice from Private Property to Street or Sidewalk
		More than one cubic yard	One cubic yard or less
Commercial	$200*	$200*	$150*
Residential with More than 16 Units	$100*	$150*	$100*
Residential with 16 or Fewer Units	$50*	$100*	$50*
*Each day that a violation exists is considered a separate and distinct violation

Many municipalities have programs to assist low-income elderly or disabled people with sidewalk, walkway and driveway snow removal. Snow Angels,²³ Snow/Ice Busters,²⁴,Snow Buddy,²⁵ and Shovel our Snow²⁶ are just a few names of programs throughout the nation. These programs are for residents who cannot physically or financially perform sidewalk snow removal. For those in need, an application is often required to demonstrate eligibility. Some jurisdictions provide an online questionnaire to match volunteers with those in need of help, such as the City of Chicago's Snow Corps program. Snow removal may be performed by city sponsored contracted services, city crews, neighbors, youth groups or volunteers. Assistance programs, whether highly organized or informal, not only help elderly or disabled residents and ensure snow removal will be performed consistently, but are also good community building and service opportunities.

Snow Removal from Shared Use Paths

Shared use paths are often treated differently than sidewalks after snow events. In many communities they are either not plowed or have a very low priority of being plowed. Seldom do communities require adjacent property owners to maintain them. Some communities, counties, and states deliberately do not clear pathways to allow for winter activities such as skiing or snowmobiling. Decades ago, very few paths were maintained for year-round use. However, as more and more paths became true transportation facilities and are funded with transportation funding, that practice began to change. Several factors need to be considered when deciding on removal of snow from paths.

• Bicyclist and pedestrian demand for the facility. Facilities located in remote areas will have little winter demand while those located within urban areas will see continued demand throughout the winter, especially from pedestrians.
• Presence of nearby pedestrian facilities. If there are no nearby sidewalks that parallel the path and can act as an alternate facility, having a path maintained year-round becomes more important.
• Community support. Are neighborhoods, bicyclists, and pedestrians asking that the facility be cleared of snow and ice? Are there many requests for maintaining the path for winter use?
• Connectivity. The more neighborhoods and commercial areas the path connects to, the more valuable the path will be for year-round use.

Paths that are located within the public right-of-way often substitute for a sidewalk and need to be cleared of snow and ice in the same timeframe as sidewalks. Since paths are wider than sidewalks, wider pieces of equipment can service it such as pick-up trucks with mounted plows. This is also a reason why paths should be designed with appropriate widths and loading characteristics to accommodate light-duty equipment (see sections 6.1 and 6.2).

Snow and Ice Removal – Conclusion

Depending on the region, snow and ice removal can be a major seasonal effort for communities of all sizes. The preceding sections include the basic elements of a recommended snow removal program. Most of these elements can at least in part be employed in communities of all sizes.

The most equitable means of removing snow and ice from sidewalks and paths is to have a community-sponsored program. This will better ensure a consistent removal of snow and ice. In many states, the local community is ultimately responsible for snow removal, but has shifted the initial responsibility to the adjacent property owner. Although community sponsorship of snow removal is recommended based on its fairness, the vast majority of communities will still require adjacent property owners to remove snow and ice. When that is the case, communities have several primary responsibilities:

• Clear snow and ice from their own sidewalk facilities, median crossings, and splitter islands
• Ensure through compliance measures that snow is being removed
• Remove snow and ice from sidewalks, bridges and curb ramps where adjacent property owners fail to do so
• Provide education programs on importance of removal and proper ways of removing snow and ice
• Coordinate with other public entities to make sure all jurisdictions are providing for removal on their publically owned facilities
• Provide a problem reporting system both on-line and via phone
• Sponsor assistance programs for people who cannot remove snow and ice themselves

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¹⁶Cuelho, Eli, Jerry Stephens and Charles McDonald. "A Review of the Performance and Costs of Contemporary Pavement Marking Systems." Western Transportation Institute. Boseman, MT. 2003.

¹⁷Montebello, David and Jacqueline Schroeder. "Cost of Pavement Marking Materials." Minnesota Department of Transportation. 2000.

¹⁸ http://mutcd.fhwa.dot.gov/knowledge/faqs/faq_part4.htm#q22

¹⁹ New Hampshire State Title XX section 231:113 http://www.gencourt.state.nh.us/rsa/html/XX/231/231-113.htm

²⁰ http://www.clrp.cornell.edu/workshops/manuals/snow_and_ice_control.pdf

²¹ http://www.ipa.udel.edu/publications/SnowRemoval.pdf

²²http://www.mnltap.umn.edu/publications/handbooks/documents/snowice.pdf

²³ Pittsburg, PA http://www.pittsburghpa.gov/servepgh/snowangels/

²⁴ Aurora, CO https://www.auroragov.org/LivingHere/GivingBack/SnowBusters/

²⁵ Boulder Colorado. Link no longer available.

²⁶ Brookline MA, http://www.brooklinema.gov/index.php?option=com_content&view=article&id=193&Itemid=877

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