Speed Management ePrimer for Rural Transition Zones and Town Centers – Module 6

6 Selected Speed Management Case Studies

The following four case studies show different approaches towards addressing speed management within the community. Figure 5-1 notes the variety of approaches which include:

• Community initiative.
• Rural area evaluation.
• Strategic planning.
• Engineering study.

A brief summary is provided for each case study, followed by a hyperlink to a report or other document that provides additional detail.

Table 6-1 Case Study Summary

											Traffic Calming Treatments
				Public Concerns							Horizontal Deflection								Vertical				Markings						Signage				Other
Case Study	Unique Approach and Focus Areas for the Countermeasure	Location	Summary	Speeding	Safety	Transition Zone	Traffic Volumes (through)	Cut Through Traffic	Reduce Truck Traffic	Existing TCDs or Calming	Road Closures	Roadway Realignment	Roundabout	Median Barrier/Island	Chicane	One Way Roadway	Lane Narrowing	Lane Delineators (bike lane)	Speed Hump	Speed Table	Speed Cushions	Pedestrian Crossings (raised)	Pavement Markings Improved	Pvmt Mkg (SLOW)	Pvmt Mkg (Optical Bar)	Pvmt Mkg (Chevron)	Pvmt Mkg (Transverse Bar)	Pvmt Mkg (Speed Limit)	Speed Limit Reduction	Speed Feedback Signs	Special Signing	Gateway Signing	Turn Restrictions	Back-In Angle Parking	Landscaping
1	Approach: Community Initiative Focus Area: Comprehensive	Village of Palmetto Bay, Florida (Community)	Organized community calming initiatives and process (2015).	X		X	X		X	X		X	X		X	X		X		X		X	X						X				X
2	Approach: Rural Area Evaluation Focus Area: Rural Community	Kitsap Co, Washington (Rural Area)	Assess safety, evaluate existing TCDs and calming measures (2013).	X	X					X										X										X
3	Approach: Strategic Planning Focus Area: Urban/Rural Areas	Princeton Township, New Jersey (Corridor)	Vision Plan contains a series of traffic calming elements in different settings (2006).	X	X	X	X	X	X				X	X																				X	X
4	Combines four studies Approach: Engineering Study Focus Area: Transition Zones	City of Jesup, Iowa (Transition Zone)	Speed advisory pavement markings at transition zones in Jesup, Iowa (2012).	X	X	X																						X
		City of Ossian, Iowa (Transition Zone)	Speed advisory pavement markings at transition zones in Ossian, Iowa (2012).	X	X	X																						X
		City of Quasqueton, Iowa (Transition Zone)	Transverse bar pavement markings at transition zones in Quasqueton, Iowa (2012).	X	X	X																						X
		City of Dexter, Iowa (Transition Zone)	Speed advisory pavement markings at transition zones in Dexter, Iowa (2012).	X	X	X																						X

6.1 Village of Palmetto Bay, Florida

Approach: Community Initiative

Focus Area: Comprehensive across Village

Summary: Organized community speed management initiative and process (2015)

What is unique about the approach?

The Village of Palmetto Bay, FL (population 24,339) has a community-based initiative towards speed management in which the Police and Public Works Department receive requests from residents for speed management projects and jointly handles responsibility for addressing these issues. The Village defines speed management as:

• The combination of non-physical and physical measures that reduce the negative effects of vehicle use, alter driver behavior, and improve conditions for non-motorized street users.
• Tools that attempt to slow traffic within residential communities with minimal restriction to access.

What is the speed management focus area?

The Village approach addresses speeding concerns comprehensively with the following options available to address issues:

• Enforcement: police officers monitor and enforce speed limits.
• Non-physical measures: low-cost measures such as pavement markings to narrow travel lanes.
• Physical measures: road redesign that create a vertical or horizontal shift in the travel lanes.
• Alternative actions: major road improvements are considered typically when traffic volumes exceed 1,050 vehicles per day, which is the Village standard; county standard is 1,500 vehicles per day.

When was the initiative established and what are the citizen concerns?

The Village organized their community scale speed management initiatives and process in June of 2015. The main concerns from residents include:

• Speeding.
• Traffic volumes on local roads during peak hours.
• Traffic circle delays.
• Oversize vehicles using local roads.
• Missing traffic signs.
• Unmarked crosswalks.
• Traffic signal timing.
• Conditions near schools (blocked driveways, Illegal U-turns, blocked sidewalks, off-road parking).

What speed management strategies are being used?

The community has strategies to both reduce speed and volumes on residential streets. The speed management efforts to date include the following strategies:

• Roadway Realignment.
• Chicane.
• Speed Tables.
• Roadway Striping.
• Roundabout.
• Speed Limit Reduction.
• Turn Restrictions
• One Directional Roadway
• Solar Pedestrian Crossings

The Village has established both short- and long-term priorities which include:

• Short-Term: Cut ThroughtTraffic, speeding, bike lanes, speed reduction.
• Long-Term: Work toward complete streets.

Several temporary speed management strategies are available to residents as noted below:

• Speed Humps (slow down cars on residential streets).
• Speed Tables (flat-topped speed humps for more gradual speed reduction which being installed in 2015).
• Series of small speed humps (slow down cars, without impeding emergency vehicles).
• Lane Delineators (separate bike and vehicle lanes to protect bicyclists).

How do citizens request a speed management device?

Palmetto Bay citizens can call and specific to speed tables accept Temporary Speed Table Applications from residents who believe there is excessive speeding or poor traffic conditions present in their neighborhood. In order to install the temporary speed table(s), the application requires a 67 percent approval from the neighbors of the area in question. Once the Public Services Department verifies the application, the area(s) get placed on a list with a contractor for installation. However, in order to install permanent asphaltic speed tables, the area must be reviewed for excessive speeding and poor traffic conditions. If it qualifies, the request must then be put forth by Resolution of the Village Council.

6.2 Kitsap County, Washington

Approach: Rural Area Evaluation

Focus Area: Rural Community including Non-Motorized Facilities

Summary: Completed a study to access safety, evaluate existing traffic control devices, and to establish speed management measures (2013)

What is unique about the approach?

Comprehensive assessment of traffic safety issues, and an evaluation of the existing traffic control devices and speed management measures (speed tables). The 2013 study includes pedestrian and bike considerations. The previous reviews and analysis, within the rural study area, were completed by the County Public Works Department. This study, completed by a consultant (TranspoGroup) provides an opportunity for the County and residents of the study area to have an independent and comprehensive review of the roadway conditions, vehicle speeds, safety issues, and existing traffic control and speed management measures along the arterial roadways. The effort identifies best practices for speed management measures along primary routes within rural areas.

What is the speed management focus area?

The study focuses on the Greater Hansville Area (GHA), an unincorporated community in Kitsap County located at the northern end of the Kitsap Peninsula. The traffic study area is an approximately 11 mile network of arterial roadways located in the GHA often referred to as the "Hansville Loop." The arterial network of roads provides primary access to the neighborhoods, adjoining residential properties, small commercial areas, parks, and public community spaces.

When was the initiative established and what are the citizen concerns?

The study was completed in 2013 and one component included an online survey to capture public perceptions about traffic and to help identify parameters for what the traffic study should evaluate and consider. The survey included approximately 18 questions to understand how area residents used the roadways and their general impressions regarding safety. It also attempted to better prioritize specific issues they would like addressed. The County received approximately 330 responses with the primary concerns noted as:

• Vehicle speeds.
• Safety.
• Existing speed management installed source of debate and concern.

What are the study recommendations relative to speed management?

The community has strategies to both reduce speed and volumes on residential streets. The speed management efforts to date include the following strategies:

• In rural areas where alternate routes do not exist, speed management device selection is important to maintain the intended use and function of the roadway.
• Speed tables are effective in reducing vehicle speed, although they have a limited influence area. Ultimately, they reduce speed of all road users, even those traveling the posted speed limit.
• Speed tables should not be the first consideration to reduce vehicle speeds. Public support is necessary for successful implementation. Some agencies require up to 80 percent acceptance for a speed table to be installed.
• The following criteria should be considered to determine if a speed management device is appropriate:
  • Public involvement.
  • Traffic characteristics.
  • Emergency vehicle access.
  • Design.
  • Application.
• The County should work to complete and implement administrative policies for setting or modifying speed limits to provide more consistency in how and when speed limit changes are made along County roadways. Incorporate the rural arterial speed management toolbox into County processes and procedures to better identify applicable speed management measures that can be considered for rural arterials.

How do citizens request a speed management device?

Kitsap County periodically receives requests from its citizens or local community organizations asking that posted speed limits be modified along a corridor. Typically the requests are associated with concern about high vehicle speeds along a roadway. The online survey conducted by the County in May 2012 indicated that few respondents were concerned about the existing speed limits on the roadways today, but were rather concerned about the enforcement of existing speed limits. Kitsap County has not adopted policies or guidelines that need to be followed when modifying or setting speed limits. Instead the County follows Washington State law (WAC 468-95-045), which requires an engineering and traffic investigation to determine if a speed limit modification is warranted. Such an investigation is usually conducted only for those locations that have seen some noticeable change in development, land use, collisions type and frequency, roadway realignments, or travel behavior.

What are the applicable speed management measures for rural arterials?

The study includes development of a speed management toolkit for rural arterials as summarized below:

• Police Enforcement.
• Speed Radar Signs.
• Medians / Gateway Treatments.
• Roadway Narrowing.
• Speed Limit Pavement Markings.
• Roundabouts.
• Speed Dots - Circular or oval in shape and are placed along the centerline of a roadway at a mid-block location. The purpose of the dots is to reduce the width of the roadway and require vehicles to maneuver around the feature.
• Speed Tables / Split Speed Tables.

6.3 Mercer County, New Jersey

Approach: Strategic Planning

Focus Area: Route 206 Corridor (Urban and Rural Segments)

Summary: Vision plan which contains a series of speed management elements in both rural and urban settings (2006)

What is unique about the approach?

Princeton Township, Princeton Borough, and the advocacy group Citizens for a Safer Route 206, requested assistance from the New Jersey Department of Transportation to develop a comprehensive vision for Route 206. The Route 206 Joint Vision Plan and Traffic Calming Study takes a corridor level approach to finding solutions to local concerns through three objectives:

• Set the community context for recommendations.
• Assess the performance of various concepts.
• Provide the basis for the local entities to work together in planning, prioritizing, and advancing the Vision Plan elements.

What is the speed management focus area?

Route 206 from the Nassau Street intersection area in Princeton Borough to Cherry Valley Road in Princeton Township. The route was defined as a series of five sub-areas from the southern end of the corridor to the north: "In-Town Residential," "Civic Park," "Neighborhood Commercial/Rural Residential," "Woodland," and "Northern Commercial." The Vision Plan contains a series of speed management elements (street trees, roundabouts, back-in angled parking, and pedestrian median refuges) designed to slow vehicular traffic and increase safe opportunities for pedestrians.

What were the citizen concerns?

The study includes a collaborative public involvement process with two design workshops and interviews with local government staff and elected officials, business owners, residents, emergency services representatives, maintenance staff, school system representatives, and the local and regional planning agencies. Several common themes became apparent in the stakeholder interviews:

• Discourage cut-through traffic.
• The noise and volume of truck traffic, and the potential for even more truck traffic.
• Safety concerns generated by the volume and speed of traffic, dangerous driving practices and the current engineering solutions on the road, which cause drivers to speed.
• A high crash rate.
• The "barrier" effect of the road: the large volume of fast-moving vehicles pose a challenge for other modes of travel and divides formerly unified residential areas.
• Piecemeal changes to the roadway to address problems at specific locations; over time these changes have challenged the relationship of the road to the community around it, compromising the quality of life in Princeton.

What are the study recommendations relative to speed management?

Although each segment of the Route 206 corridor has its own set of unique characteristics and challenges, several speed management measures were identified as common solutions and were emphasized throughout the corridor. These include:

• Roundabouts.
• Street trees.
• Back-in angle parking.
• Pedestrian median refuge.

What does the Vision Plan provide?

The ideas embodied in the Vision Plan are intended as a starting point from which community residents and their elected officials and their planners can create a "form-based comprehensive plan" of images which illustrate how the corridor might appear. Each particular idea needs to be refined through community analysis, further impact analysis, and the project development process.

The Vision Plan provides Princeton with a framework that allows residents and officials to think about proposed changes in a comprehensive manner. The hope is that this Vision Plan will help the Princeton community come to an agreement on elements to be integrated into its master plan and that it will guide NJDOT in implementing needed projects along the corridor.

The document first defines the design elements that shape the Vision, and then lays out the possible applications of these elements. The speed management elements per area are summarized below:

• In-Town Residential Area - street width of 33 feet, mid-block pedestrian refuges, median refuges, median island, lateral shift, roundabouts, back-in-angled parking, bulb-outs.
• Civic Park Area - street width of 24 feet, roundabout, median refuge, lateral shift, large center island.
• Rural Residential - street width of 22 feet with 5 foot sidewalk on one side, back-in angled parking, lateral shift, roundabout.
• Woodland Area - street width of 24 feet, multi-use path, pedestrian median refuge, roundabout.
• Northern Commercial Area - street width of 50 feet, pedestrian median refuge, lateral shift, back-in-angled parking, roundabout.

The study also documents the Vision Plan process including:

• Summary of Public Involvement Process and Press Coverage.
• Level of Service and crash study for existing conditions.
• Consideration of regional initiatives.
• Cost Estimate.
• Implementation Plan.

6.4 Rural Iowa Communities

Approach: Traffic engineering solutions for rural transition zones

Focus area: Transition zone

Summary: Engineering study

Why was speed management necessary?

Over 42 percent of the population of Iowa (USA) live in a city or township with a population less than 5,000 residents. Many of these communities are located on a farm to market road or principal arterial. As a result, speed management is an important piece of the puzzle to address rural traffic safety. To this end, a team of research engineers from the Institute of Transportation at Iowa State University, selected and then conducted a field evaluation of different engineering speed management countermeasures within rural communities.

How were the speed countermeasures selected?

A list of engineering speed management countermeasures appropriate for use along major routes through rural communities was compiled by the engineering team. This first included evaluating countermeasures employed in urban US communities to determine whether they were feasible for rural communities. Next European countermeasures were identified and considered in the context of rural conditions and norms in the US since rural speed management is more advanced in Europe and other countries than in the US. Countermeasures also needed to be reasonably low-cost due to project constraints (< $10,000 USD). Additionally, the countermeasure needed to conform to the Manual on Uniform Traffic Control Devices (MUTCD) or be able to receive experimental approval.

The engineering countermeasures considered include:

• Various configurations of on-pavement signing.
• Dynamic speed feedback signs.
• Optical speed bars.
• Converging chevrons.
• Dragon's teeth.
• Speed tables.
• Lane narrowing using traffic control devices such as tubular channelizers.
• Lane narrowing using pavement markings.
• Chicane countermeasure using pavement markings to create horizontal deflection path.
• Gateway entrance signing.
• Flashing beacons placed at community entrances.

How were the participating communities selected?

Each community either responded to a general study solicitation or were identified for consideration by others, most often the County Engineer.

How were the final speed management study locations selected?

The evaluation for each potential location included a combination of field and desk review actions. The field review considered the magnitude of the existing speeding problem with "speeding" defined as the mean or 85th percentile speed being 5 mph over the posted speed limit. Other considerations included proximity of the road to sensitive land uses (schools, playgrounds, or other pedestrian generators), whether the roadway geometry was conducive to installing countermeasures and measuring their benefits, the location of other traffic controls (i.e. stop signs), the vehicle volumes and fleet mix, and crash history.

The team developed a short list of potential locations and met with locals (city council, maintenance workers, citizens, and law enforcement) to gain perspective on the issues at hand and to discuss appropriate countermeasures. Based on this information, the team presented a speed countermeasure plan for Council approval as well as coordination with the County Engineer. Lastly, the Iowa DOT provided final approval to initiate each community plan. In some cases, the speed countermeasure required "experimental approval" due to non-compliance with the MUTCD.

What were the common community concerns?

Common concerns cited by the communities include:

• Speeding at the community entrances .
• Speeding within community particularly near sensitive land uses (e.g., schools).
• Safety concerns for child pedestrian and bicyclists due to high speeds within communities.
• Need to accommodate agriculture equipment.
• Large truck traffic.
• Ability of older rural drivers to understand and respond to proposed countermeasures.

There were a number of different countermeasures evaluated within community speed transition zones with the results of two different approaches summarized below.

6.4.1 Before/After Case Study #1: Horizontal Speed Limit Signage

What was the treatment?

Figure6-1 shows an example of the horizontal signing evaluated (speed advisory pavement marking treatment) which consists of a large red square painted within the travel lane along with the speed limit ("XX MPH") in white.

Figure 6-1 Horizontal signing at community entrance in Dexter, IA
[Treatment authorized with MUTCD experimental waiver]
(Image Source: Neal Hawkins)

These pavement markings are a supplement to existing signage with the unusual over-sized markings being more dramatic than static side-of-road signing which can get lost in the clutter or conditioned commuter behavior. Figure 6-2 shows an example of the marking adjacent to existing signage

Figure 6-2 Horizontal signing at community entrance in Ossian, IA
[Treatment authorized with MUTCD experimental waiver]
(Image Source: Hallmark, et al 2002)

Where was the treatment installed?

Horizontal signing was applied at the speed transition zone of the major roadway entering a small rural community. Table 6-2 identifies the five evaluation locations within the three different communities.

Table 6-2 Evaluation locations for horizontal signing

City	Community Approach	Roadway	AADT (vpd)	Speed Limit (in transition zone)
Dexter	West	F-65	1,100	55 mph to 35 mph
Dexter	East	F-65	1,300	55 mph to 35 mph
Jesup	East	SH 939	2,850	45 mph to 35 mph
Jesup	West	SH 939	3,070	45 mph to 35 mph
Ossian	North	W-42	840	55 mph to 25 mph

How were the markings installed and was maintenance over time an issue?

The pavement markings were installed in Dexter first using standard traffic paint, however, winter maintenance significantly degraded their presence after one winter, see Figure 6-3.

Figure 6-3 Pavement marking paint installation (left) and wear after one winter (right)
[Treatment authorized with MUTCD experimental waiver]
(Image Source: Neal Hawkins)

To avoid the problem of wear over time, and to increase skid resistance across the large painted surface, the team used pre-formed thermoplastic with skid resistance for all subsequent pavement marking installations, see Figure 6-4.

Figure 6-4 Thermoplastic pavement marking installation
[Treatment authorized with MUTCD experimental waiver]
(Image Source: Hallmark, et al. 2002)

How was the evaluation conducted?

The evaluation compares speed metrics from before and after installation. Pneumatic road tubes provided individual vehicle speeds, classification, and volume by time of day. The information contrasted included mean and 85^th percentile speeds as well as the fraction of drivers traveling 10 or more mph over the posted speed limit (reflects reduction in high-end speeding and not just average changes in speed).

What were the results of the evaluation?

Table 6-3 summarizes the change in speed metrics 12 months after installation. This includes the mean and 85^th percentile speed as well as the impact on the higher end speeds (percent traveling 10 and 15 mph over the posted speed). As shown, mean speeds decreased by 1 and up to 2 mph as compared to the before period, and 85th percentile speeds decreased by 1 and up to 3 mph. More positively, there was a sustained reduction in the percentage of vehicles traveling 10 or 15 mph over the posted speed limit (up to 54 percent for 10 mph and up to 53 percent for 15 mph).

Table 6-3 Horizontal signing effectiveness showing change from before to 12 months after installation

City	Approach	Roadway	Mean Speed (mph)	85th % Speed (mph)	% 10 mph over posted speed	% 15 mph over posted speed
Dexter	West	F-65	-1	-1	-13%	-16%
Dexter	East	F-65	-1	-1	-46%	0%
Jesup	East	SH 939	-1	-1	-43%	-53%
Jesup	West	SH 939	-2	-3	-54%	-52%
Ossian	North	W-42	-1	-1	-17%	-17%

6.4.2 Before/After Case Study #2: Removable Traffic Control Devices

What was the treatment?

Figure 6-5 shows an example of how removable traffic control devices were used to create a sense of narrowed lanes and transition zone awareness as drivers entered the community. The temporary curbing was yellow in color and approximately 2 inches high by 40 inches long by 8 inches wide with reflectorized material on each end. Hazard markers were secured on flexible mounts at the beginning and end of the countermeasure.

Figure 6-5 Removable traffic control device countermeasure installed in St Charles, IA
(Image Source: Hallmark et al. 2013)

Where was the treatment installed?

The treatment was installed at the speed transition zones on the north, south, and west entrances to St. Charles, Iowa (pop = 653). The east community entrance includes a horizontal curve and was not considered for the treatment.

How were the markings installed and was maintenance over time an issue? The countermeasure was easily installed using simple tools and followed manufacturer's instructions. The countermeasure was placed to avoid driveways (both residential and farm driveways) and drainage facilities. Following installation, some farmers expressed concerns about moving loaded trucks across the countermeasure during the fall harvest. Additionally, it was originally intended that the countermeasure would be removed during the winter months since it could not be avoided by snow plows. As a result, the countermeasure was removed during the late fall and winter periods and replaced during the spring. The plastic products were durable, however, given the potential for the object marker signs to be damaged, additional supplies were ordered and stockpiled.

How was the evaluation conducted?

The evaluation compares speed metrics from before and after installation. Pneumatic road tubes provided individual vehicle speeds, classification, and volume by time of day. The information contrasted included mean and 85^th percentile speeds as well as the fraction of drivers traveling 10 or more mph over the posted speed limit (reflects reduction in high-end speeding and not just average changes in speed).

What were the results of the evaluation?

Table 6-4 summarizes the change in speed metrics 12 months after installation. This includes the mean and 85^th percentile speed as well as the impact on the higher-end speeds (percent traveling 10 and 15 mph over the posted speed). As shown, mean speeds decreased by 1 and up to 3 mph as compared to the before period, and 85th percentile speeds decreased by 1 and up to 3 mph. More positively, there was a sustained reduction in the percentage of vehicles traveling 10 or 15 mph over the posted speed limit (up to 50 percent for 10 mph and up to 57 percent for 15 mph).

Table 6-4 Removable traffic control device effectiveness showing change from before to 12 months after installation

Community Approach	Roadway	Mean Speed (mph)	85th % Speed (mph)	% 10 mph over posted speed	% 15 mph over posted speed
North	Morgan	-3	-3	-50%	-57%
South	Morgan	-2	-2	-33%	-43%
West	Main	-1	-1	-22%	-25%

 

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