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Home > Intersections > Resources

Example Intersection Safety Implementation Plan

Implementation

The successful implementation of the multiple strategies in the plan will require constant and broad management support. It is expected that as the effort is implemented, unforeseen problems will arise, new opportunities will develop, and changes in direction and emphasis will be needed to take advantage of changing conditions. As such, the following actions should be taken to ensure success.

• A Highway Safety Committee comprised of the following members should provide guidance and address issues and problems that arise during the implementation of the program. The Committee should meet on a planned quarterly basis throughout the implementation phase.
  • Office of Safety.
  • Office of Traffic Engineering Operations.
  • Governors Highway Safety Representative.
  • Federal Highway Administration (FHWA) Safety Representative.
  • District Traffic/Safety Representative.
• The State DOT Office of Safety should develop and deploy a tracking system to monitor the implementation of the various types of countermeasures being deployed. This system should include forms designed to secure before and after targeted crash histories, dates of implementation, linkages to other improvements implemented at the intersection, and other information deemed pertinent by the Highway Safety Committee.

The remainder of this section provides a detailed description of and key implementation steps for each countermeasure to be implemented. A tabulation of the countermeasures and type of approach is shown in Table 6.

1. Sign and Marking Improvements – State Stop-Controlled Intersections

Description

Basic Set of Signing and Marking Improvements

This initiative involves the installation of a set of basic signing and marking improvements that are collectively low-cost, designed to lower the potential of future crashes significantly, and are to be applied predominantly on single through lane, high-crash, stop-controlled State intersections in both rural and urban areas. They may also be applied on dual through lane, high-crash, stop-controlled intersections with lower traffic volumes (less than about 25,000 average annual daily traffic (AADT)) where the use of J-treatments is not appropriate and the frequency of acceptable gaps for entering traffic is such that long waiting and higher risk taking are not present at the intersection.

Figure 1. Examples of Basic Low-Cost Countermeasures for Stop-Controlled Intersections – Double Up Oversize Warning Signs, Double STOP Signs, Traffic Island on Stop Approach (if feasible), Street Name Signs, Stop Bars, and Double Warning Arrow at the Stem of T-Intersections

Basic enhancements considered for improvement are illustrated in Figure 1 and include the following:

• Through approach.
  • Doubled up (left and right), oversize advance intersection warning signs, with street name plaques.
• Stop approach.
  • Doubled up (left and right), oversize advance "Stop Ahead" intersection warning signs.
  • Doubled up (left and right), oversize STOP signs.
  • Installation of a minimum 6 ft. wide raised splitter island on the stop approach (if no pavement widening is required).
  • Properly placed stop bar.
  • Removal of any foliage or parking that limits sight distance
  • Double arrow warning sign at stem of T-intersections.

The high-crash intersections where the basic set of signing and marking improvements are to be considered for installation are summarized in Table 7. The State Safety Engineer has a complete listing of all intersections with numbers of crashes that meet or exceed the threshold levels in this and all remaining tables. In addition to this listing, detailed crash information for each crash that occurred at these intersections is also available.

Table 7: Basic Set of Sign and Marking Improvements – State Stop-Controlled Intersections

Countermeasure	Threshold Crash Level (6 Years)	Number of Statewide Crash Intersections	Number of Targeted 6 Year Crashes in the Intersections	Estimated Number of Improvements1	Construction Costs ($ Million)2	Fatalities per 100 Crashes	Incapacitating Injuries per 100 Crashes	Annual Targeted Crash Reduction3	Annual Incapacitating Injury Reduction	Annual Estimated Fatality Reduction
Basic Set of Sign and Marking Improvements – Rural	6	1,221	13,722	977	7.82	1.6	12.47	732	91.2	11.71
Basic Set of Sign and Marking Improvements – Urban	50	165	12,180	131	1.05	0.21	3.31	650	21.5	1.36
Total				1,108	8.87			1,382	117.7	13.07
1 Assumes 80% of locations can be improved. 2 Assumes an average cost of $8,000 per intersection. 3 A CRF of 0.40 is used.

Flashing Solar Powered LED Beacons on Advance Intersection Warning Signs and STOP Signs or Flashing Overhead Intersection Beacons

In addition to the basic sign and marking enhancements at State stop-controlled intersections, this initiative also involves the installation of supplemental warning notification for the traveling public at State stop-controlled intersections with a number of crashes that is well beyond the crash threshold for sign and marking enhancements. The enhanced warning notifications may be either solar-powered LED flashing beacons placed on the oversized advance warning signs for the through approach, or they could be a combination of both presence detectors on the stop approach that recognize a stopped vehicle and activated LED flashing beacons on advance warning signs on the through approach. Flashing beacons may also be placed on the STOP signs if running STOP signs is a significant problem and transverse rumble strips are not appropriate due to noise issues.

The high-crash intersections where flashing beacons are to be considered for installation are summarized in Table 8.

Table 8: Flashing Beacons – State Stop-Controlled Intersections

Countermeasure	Threshold Crash Level (6 Years)	Number of Statewide Crash Intersections	Number of Targeted 6 Year Crashes in the Intersections	Estimated Number of Improvements1	Construction Costs ($ Million)2	Fatalities per 100 Crashes	Incapacitating Injuries per 100 Crashes	Annual Targeted Crash Reduction3	Annual Incapacitating Injury Reduction	Annual Estimated Fatality Reduction
Flashing Solar Powered LED Beacons on Advance Intersection Warning Signs and STOP Signs or Flashing Overhead Intersection Beacons – Rural	24	66	2,261	52	0.52	1.6	12.47	24	3	0.38
Flashing Solar Powered LED Beacons on Advance Intersection Warning Signs and STOP Signs or Flashing Overhead Intersection Beacons – Urban	100	21	2,842	17	0.17	0.21	3.31	30	1	0.06
Total				69	0.69			54	4	0.44
1 Assumes 80% of locations can be improved. 2 Assumes an average cost of $10,000 per intersection. 3 A CRF of 0.08 is used – 0.13x(1-0.40)=0.08.

Optional Signing and Marking Improvements Based on the Characteristics of the Intersection

The optional additional improvements listed below may be beneficial if specific intersection safety concerns are present. These improvements should be considered for each stop-controlled intersection with a number of crashes that meets or exceeds the threshold. The determination to include one or more of these improvements cannot be determined from the crash data; it must be made after a field review of the intersection to identify physical, traffic, or pedestrian characteristics that merit inclusion.

• Placing reflective strips on sign posts if sign visibility due to a competing background may be a concern.
• Installing peripheral transverse markings or narrowing the approach lane width by reconfiguring the lane lines on the through approach if entry speeds are high.
• Applying rumble strips or transverse pavement markings on the stop approach if running the STOP sign is a problem and noise is not an issue.

Key Implementation Steps

The key steps necessary to fully implement this initiative and realize the safety benefits of the improvements, the organizations responsible for each key step, and the schedule to implement this activity fully are shown in Table 9.

2. J-Turn Modifications on High-Speed Divided Arterials – State Stop-Controlled Intersections

Description

This initiative involves the installation of minor channelization on the stop approaches to multi-lane, divided, high-speed highways to make them right-turn only. This treatment is considered at those intersections which have 10 or more crashes involving a stopped vehicle in a 6-year period. Left-turn and through movements from the stop approach are eliminated by minor channelization and signing. This option is feasible where vehicles can reach their intended destination by turning right at the intersection and within a reasonable distance downstream, enter an exclusive left-turn lane, and make a U-turn. Figure 2 provides an illustration.

Figure 2. Turn Restrictions at Multi-Lane Highways

The J-turn treatment is considered the most effective low-cost countermeasure treatment available for reducing future crash potential at divided highway intersections. However, if left-turn lanes for the turnarounds are not available within a reasonable distance and the costs to install new lanes is prohibitive, or if significant controversy is involved with limiting movements at the intersection, less effective countermeasures can be considered as follows:

• Install sign and marking improvements together with flashing beacons similar to those described in the sign and marking improvements countermeasure. Also, if intersection approach speeds are high, consider adding countermeasures to reduce intersection approach speeds on the through approaches (e.g., peripheral transverse pavement markings, lane narrowing techniques, or "SLOW" pavement marking legends).
• Install presence detectors on the stop approaches that activate flashing beacons on a warning sign for the through approach, giving through motorists additional warning that a vehicle on the stop approach is present and may enter the intersection.
• Consider adding a traffic signal if the intersection meets the Manual on Uniform Traffic Control Devices (MUTCD) signal warrants.

The high-crash intersections where J-treatments should be considered are summarized in Table 10.

J-turn treatments also should be considered for any divided, urban, stop-controlled intersection that has a legal speed limit of 45 mph or greater and meets the rural crash thresholds indicated in Table 10.

The severity of crashes at rural stop-controlled intersections is extremely high (i.e., 3.74 fatalities per 100 crashes). As such, the three additional options listed above should be considered at all divided rural intersections and divided urban intersections with speed limits of 45mph or greater with 5 or more crashes in a 6-year period when it is not feasible to install J-turn treatments.

Key Implementation Steps

The key steps necessary to fully implement this initiative and realize the safety benefits of the improvements, the organizations responsible for each key step, and the schedule for this activity are shown in Table 11.

3. Basic Set of Sign and Marking Improvements – Local Stop-Controlled Intersections

Description

This initiative involves the installation of a set of signing and marking improvements that are low-cost, designed to lower the potential of future crashes significantly, and are to be applied predominantly on single through lane, high-crash, stop-controlled local intersections in both rural and urban areas. They utilize the same basic set of sign and marking improvement countermeasure treatments and the same crash threshold levels as those described for State stop-controlled intersections in Countermeasure #1.

Since the level of effort to obtain Federal funds for multiple low-cost improvements on local roads and transfer them to local governments may exceed the costs of the low-cost improvements, the State initiative will include the following:

• An assessment of the potential for manufacturing the appropriate signs by the State Sign Shop using 100 percent Federal funds for local use at the designated intersections.
• Distribution of information on the high-crash intersection locations to appropriate local governments and guidance on low-cost sign and marking enhancements to reduce future crash potential.
• Coordination and facilitation of local government training either by the Local Technical Assistance Program (LTAP) or the FHWA Resource Center on the application of low-cost countermeasures at the high-crash intersections.

The high-crash intersections where the basic set of sign and marking should be considered are summarized in Table 12.

Table 12. Basic Set of Sign and Marking Improvements – Local Stop-Controlled Intersections

Countermeasure	Threshold Crash Level (6 Years)	Number of Statewide Crash Intersections	Number of Targeted 6 Year Crashes in the Intersections	Estimated Number of Improvements1	Construction Costs ($ Million)2	Fatalities per 100 Crashes	Incapacitating Injuries per 100 Crashes	Annual Targeted Crash Reduction3	Annual Incapacitating Injury Reduction	Annual Estimated Fatality Reduction
Basic Set of Sign and Marking Improvements – Rural	6	190	1,968	152	1.22	0.21	5.23	105	5.5	0.22
Basic Set of Sign and Marking Improvements – Urban	50	105	7,683	84	0.67	0.12	2.35	410	9.6	0.49
Total				236	1.89			555	15.1	0.71
1 Assumes 80% of locations can be improved. 2 Assumes an average cost of $8,000 per intersection. 3 A CRF of 0.40.

Key Implementation Steps

The key steps necessary to fully implement this initiative and realize the safety benefits of the improvements, the organizations responsible for each key step, and the schedule for this activity are shown in Table 13.

4. Signal and Sign Improvements – State Signalized Intersections

Description

Basic Set of Signal and Sign Improvements

This initiative involves the installation of a basic set of signal, sign, and marking improvements that are low-cost, are designed to lower the potential for future crashes significantly, and are to be applied at high-crash, signalized, State intersections in both rural and urban areas.

The typical improvements considered for implementation include:

• Back plates for all signal heads (may be reflectorized).
• 12-inch LED lenses.
• At least one signal head per approach lane.
• Signal clearance timing in accordance with Institute of Transportation Engineers (ITE) clearance formula.
• Elimination of flashing operation during night conditions.

The majority of traffic signals on the State highway system already have the first three of the suggested enhancements described above installed. Consequently improvements, costs, and safety impacts for implementing the basic set of signal and sign enhancements are minimal. The two improvements expected to have the highest level of impact are signal clearance timing in accordance with the ITE clearance formula and eliminating late-night flashing operations.

The high-crash intersections where the basic set of signal and sign should be considered are summarized in Table 14.

Table 14. Basic Set of Signal and Sign Improvements – State Signalized Intersections

Countermeasure	Threshold Crash Level (6 Years)	Number of Statewide Crash Intersections	Number of Targeted 6 Year Crashes in the Intersections	Estimated Number of Improvements1	Construction Costs ($ Million)2	Fatalities per 100 Crashes	Incapacitating Injuries per 100 Crashes	Annual Targeted Crash Reduction3	Annual Incapacitating Injury Reduction	Annual Estimated Fatality Reduction
Basic Set of Signal and Sign Improvements – Rural	10	123	3,012	98	0.49	0.41	5.53	75	4.1	0.31
Basic Set of Signal and Sign Improvements – Urban	50	371	28,570	297	1.48	0.17	3.36	714	24.0	1.21
Total				395	1.97			789	28.1	1.52
1 Assumes 80% of locations can be improved. 2 Assumes an average cost of $5,000 per intersection. 3 A CRF of 0.15.

Optional Signal and Sign Improvements Based on the Characteristics of the Intersection

The optional additional improvements listed below may be beneficial if specific intersection safety concerns are present. These improvements should be considered for each signalized intersection with a number of crashes that meets or exceeds the threshold. The determination to include one or more of these improvements cannot be determined from the crash data; it must be made after a field review of the intersection to identify physical, traffic, or pedestrian characteristics that merit inclusion.

• Advance intersection warning signs doubled up for isolated rural high speed intersections.
• Advance cross street name signs for high-speed approaches on arterial highways.
• Advance left and right Signal Ahead oversize warning signs for isolated traffic signals or intersections where the signal heads are not readily visible due to alignment or sight distance obstructions.
• Supplemental signal heads where normally placed signal heads may be difficult to identify due to sight distance limitations, horizontal curvature, or other obstructions; for exceptionally wide intersections where a near side signal is needed.
• Signal coordination improvements on high-volume, high-speed arterials with closely spaced traffic signals and frequent mainline stopping due to poor or no signal coordination.
• Pedestrian countdown signals at intersections with high pedestrian activity or multiple pedestrian crashes.
• Exclusive pedestrian phasing at intersections with multiple pedestrian-vehicle conflicts.
• Higher visibility crosswalks and advance pedestrian warning signs at intersections with high pedestrian activity or multiple pedestrian crashes.

Change of Permitted and Protected Left-Turn Phase to Protected Only

One major crash pattern that needs to be addressed individually is signalized intersections with a significant number or potential for left-turn, opposing-flow crashes. At these traffic signals the potential change is to modify the signal phase from permitted and protected left-turn phases to protected-only. This can be considered for intersections with high numbers of left-turn, opposing flow crashes, three or more opposing approach lanes, or high opposing volumes with few acceptable turning gaps.

The high-crash intersections where the protected only left-turn phase should be considered are summarized in Table 15.

Table 15. Change of Permitted and Protected Left-Turn Phase to Protected Only – State Signalized Intersections

Countermeasure	Threshold Crash Level (6 Years)	Number of Statewide Crash Intersections	Number of Targeted 6 Year Crashes in the Intersections	Estimated Number of Improvements1	Construction Costs ($ Million)2	Fatalities per 100 Crashes	Incapacitating Injuries per 100 Crashes	Annual Targeted Crash Reduction3	Annual Incapacitating Injury Reduction	Annual Estimated Fatality Reduction
Change of Permitted and Protected Left-Turn Phase to Protected Only – Rural	5	87	841	61	0.3	0.39	6.08	47	2.9	0.18
Change of Permitted and Protected Left-Turn Phase to Protected Only Urban	10	678	13,781	475	2.37	0.17	5.32	772	41.1	1.31
Total				536	2.67			819	44.0	1.49
1 Assumes 70% of locations can be improved. 2 Assumes an average cost of $5,000 per intersection. 3 A CRF of 0.48.

Advance Detection Control Systems – Isolated High-Speed State, Rural, Signalized Intersections

Isolated high-speed State, rural, signalized intersections with a significant number of angle crashes is another major crash pattern that needs to be addressed individually. At these traffic signals, the proposed improvement is to install an advance detection control system capable of identifying vehicles on the mainline that will violate the yellow and red change intervals and hold the onset of green on the side approaches until the violating vehicle clears the intersection.

These systems utilize sets of advanced detectors to predict when a vehicle will be in the dilemma zone at isolated high-speed rural, signalized intersections. As the green phase begins to end, the detection control sensors identify vehicles by their position, speed, and acceleration characteristics. Taking the signal timing into account, the sensors perform automated calculations to determine if the vehicle will be in the dilemma zone as the signal would normally change to red. When such vehicles are identified, logic can be incorporated into the signal controller to hold the red phase on the side street until the vehicles on the ending green phase clear the intersection, thereby avoiding a conflict with crossing traffic.

The advance detection control system has been demonstrated at eight intersections in Texas and also is also being deployed in other parts of the nation. The evaluations from the Texas demonstrations have shown significant reductions in red-light violation and crash frequencies.

Potential candidate intersections for this improvement are State, rural, signalized intersections with five or more angle crashes. The number of intersections that potentially can be considered for the advance detection control system in this plan is 67, as shown in Table 16. Since advance detection control systems are new to the State, the State DOT will pilot the system with limited deployments between now and 2011 to gain more experience with the system. The State DOT will install the advance detection control system at 10 isolated high-speed State, rural, signalized intersections.

Key Implementation Steps

5. Signal and Sign Improvements – Local Signalized Intersections

Description

Basic Set of Signal and Sign Improvements

This initiative involves the installation of a basic set of signal, sign, and marking improvements that are low-cost, are designed to lower the potential for future crashes significantly, and are to be applied predominantly on single through lane, high-crash local signalized intersections in both rural and urban areas. They utilize the same countermeasure treatments and crash threshold levels as those for State signalized intersections. In addition, low-cost pedestrian intersection treatments are to be considered, including:

• Pedestrian countdown signals.
• Crosswalks (if none exist).
• Warning signs for active pedestrian crossings.
• Potential elimination of the permissive portion of any protected/permissive turning operation phase that creates substantial conflicts with crossing pedestrians.
• Modifications to intersection approaches to reduce high approach speeds when substantive pedestrian activity is prevalent.

Since the level of effort to obtain Federal funds for multiple low-cost improvements on local roads and transfer them to local governments may exceed the costs of the low-cost improvements, the State initiative will include the following:

• An assessment of the potential for manufacturing and distributing the appropriate signs and signal materials by the State Sign Shop using 100 percent Federal funds for local use at the designated intersections.
• Distribution of information on the high-crash intersection locations to appropriate local governments and guidance on low-cost signal, sign, and marking enhancements to reduce future crash potential.
• Coordination and facilitation of local government training either by the LTAP or the FHWA Resource Center on the application of low-cost countermeasures at the high-crash intersections.

The high-crash intersections where the basic set of signal and sign improvements should be considered are summarized in Table 19.

Table 19. Basic Set of Signal and Sign Improvements – Local Signalized Intersections

Countermeasure	Threshold Crash Level (6 Years)	Number of Statewide Crash Intersections	Number of Targeted 6 Year Crashes in the Intersections	Estimated Number of Improvements1	Construction Costs ($ Million)2	Fatalities per 100 Crashes	Incapacitating Injuries per 100 Crashes	Annual Targeted Crash Reduction3	Annual Incapacitating Injury Reduction	Annual Estimated Fatality Reduction
Basic Set of Signal and Sign Improvements – Rural	10	12	291	10	0.1	0.74	1.63	8	0.1	0.06
Basic Set of Signal and Sign Improvements – Urban	50	316	24,839	253	2.53	0.22	2.93	662	19.4	1.45
Total				263	2.63			670	19.5	1.51
1 Assumes 80% of locations can be improved. 2 Assumes an average cost of $10,000 per intersection. 3 A CRF of 0.20.

Change of Permitted and Protected Left-Turn Phase to Protected Only

One major crash pattern that needs to be addressed individually is signalized intersections with a significant number or potential for left-turn, opposing-flow crashes. At these traffic signals the potential change is to modify the signal phase from permitted and protected left-turn phases to protected-only. This can be considered for intersections with high numbers of left-turn, opposing flow crashes, three or more opposing approach lanes, or high opposing volumes with few acceptable turning gaps.

The high-crash intersections where the protected only left-turn phase should be considered are summarized in Table 20.

Table 20. Change of Permitted and Protected Left-Turn Phase to Protected Only – Local Signalized Intersections

Countermeasure	Threshold Crash Level (6 Years)	Number of Statewide Crash Intersections	Number of Targeted 6 Year Crashes in the Intersections	Estimated Number of Improvements1	Construction Costs ($ Million)2	Fatalities per 100 Crashes	Incapacitating Injuries per 100 Crashes	Annual Targeted Crash Reduction3	Annual Incapacitating Injury Reduction	Annual Estimated Fatality Reduction
Change of Permitted and Protected Left-Turn Phase to Protected Only – Rural	5	8	84	6	0.03	0.51	1.02	5	0	0.03
Change of Permitted and Protected Left-Turn Phase to Protected Only Urban	10	544	11,036	381	1.91	0.2	3.83	618	23.7	1.24
Total				387	1.94			623	23.7	1.27
1 Assumes 80% of locations can be improved. 2 Assumes an average cost of $10,000 per intersection. 3 A CRF of 0.20.

Key Implementation Steps

The key steps necessary to fully implement this initiative and realize the safety benefits of the improvements, the organizations responsible for each key step, and the schedule for this activity are shown in Table 21.

6. New or Upgraded Lighting – State Rural Intersections

Description

Crashes that occur during darkness are typically more severe than daylight crashes. Major problems associated with unlit or poorly lit intersections (e.g. only one light per intersection) include reduced ability to recognize that an intersection is approaching, reduced ability to navigate turning movements properly, and degradation of the ability to recognize other vehicles and pedestrians in or entering the intersection.

The low-cost countermeasure for unlit or poorly lit intersections with a high frequency and rate of night crashes is lighting. Typical example layouts for intersection lighting are shown in Figure 3. States should follow their design policy for intersection lighting installations.

Figure 3. New Design for Intersection Lighting Layout (Single and Multi-Lane Approaches)⁴

The crash reduction factor at unlit intersections with high frequencies and rates of night crashes is 50 percent of night crashes. The crash reduction factor for improving lighting at poorly lit intersections (one existing light per intersection) is estimated by an expert safety panel as 25 percent of night crashes.

The high-crash intersections where new or upgraded should be considered are summarized in Table 22.

Key Implementation Steps

The key steps necessary to fully implement this initiative and realize the safety benefits of the improvements, the organizations responsible for each key step, and the schedule for this activity are shown in Table 23.

7. High-Friction Surface – State Intersections

Description

Crashes that occur when the pavement is wet on approaches with speed limits of 45 mph or more may be attributed to increased stopping distances due to low skid numbers and/or severe rutting in the wheel paths that might induce hydroplaning.

The low-cost countermeasure for intersections with higher frequencies of wet pavement crashes and above average wet/total crash rates include increasing the friction characteristics on intersection approaches with low skid numbers and eliminating any severe wheel path rutting.

One way transportation officials can increase pavement friction beyond what is attainable through traditional techniques is by using new high-friction surfacing systems. These systems use a combination of resins and polymers (usually urethane, silicon, or epoxy) and a binder topped with a natural or synthetic hard aggregate.

Micro texture, macro texture, and the durability of that texture distinguish these overlays from standard asphalt and concrete pavement surfaces. High-friction surfacing systems typically use much smaller and harder aggregates, such as calcined bauxite, slag, or other synthetic aggregates. These aggregates are generally less than 6.0 mm (0.23 inch) in diameter and have high skid resistance. The small and hard aggregate makes the overlay much more resistant to wear and polishing. The resin or polymer binder combination locks the aggregate firmly in place, creating an extremely rough, hard, durable surface capable of withstanding everyday roadway demands such as heavy braking and snowplowing. The rougher texture and greater surface area increase the pavement's friction.

The length of approach to apply skid resistance surfaces is variable dependent on approach speeds, sight distance, and expected queue lengths at signalized intersections. A minimum 300 feet of approach is recommended for through high-speed approaches to stop-controlled intersections. In addition, significant wheel rutting (2 inches in depth or greater) should be eliminated before applying any skid resistant surface.

Crash reduction factors for skid-resistant surfaces on high-speed (i.e., 45 mph or greater) intersection approaches with a high frequency and rate of wet pavement crashes and either (1) a ribbed tire skid number of 30 or less, (2) wheel path rutting of at least 2 inches in depth, or (3) both is 50 percent of wet pavement crashes.⁵

The high-crash intersections where high-friction surface should be considered are summarized in Table 24.

Key Implementation Steps

The key steps necessary to fully implement this initiative and realize the safety benefits of the improvements, the organizations responsible for each key step, and the schedule for this activity are shown in Table 25.

8. Enforcement-Assisted Lights

Description

This initiative involves pursuing the use of the enforcement-assisted lights for use at signalized intersections with a significant number of angle crashes over a 5-year period. Candidate municipalities with significant numbers of angle crashes are listed in Table 26.

The State has minimal experience with the use of enforcement-assisted lights. In addition, the actual effectiveness at reducing angle crashes has not been adequately validated. As such, the State DOT will proceed cautiously with deployment, initially concentrating deployment at those intersections with high numbers of angle crashes and signal designs and timing that closely conform to current best safety practices. A pilot demonstration will be deployed at approximately 50 of these signalized intersections and evaluated to determine probable effectiveness. If effective, the effort will be expanded to the remaining candidate locations.

Key Implementation Steps

The key steps necessary to fully implement this initiative and realize the safety benefits of the improvements, the organizations responsible for each key step, and the schedule for this activity are shown in Table 27.

9. Corridor 3E Improvements on High-Speed Arterials with Very High Frequencies of Severe Intersection Crashes

Description

The State DOT has identified 12 State route corridors with 7 or more fatal intersection crashes and a significant number of severe injury intersection crashes over the past 6 years though crash data analysis. The intent of this countermeasure is to advance a set of 3E initiatives on three of these corridors to reduce the potential for future severe intersection crashes. For each corridor, this initiative will have as its objective a reduction in corridor intersection fatalities and incapacitating injuries by a minimum of 25 percent using a combination of low-cost infrastructure improvements and targeted education and enforcement initiatives. While the selection of the corridors has been based upon high frequencies of severe intersection crashes, the approach may be broader and encompass other corridor concerns such as road departure, mid-block pedestrian problems, and driver behavioral problems, including driving while intoxicated, lack of safety belts, and speeding.

The effort begins with a thorough analysis of the crash characteristics in the corridor to understand better the problems that need to be addressed and relate crash patterns to potential countermeasures. Corridor safety studies usually are conducted on 5 to 20 mile sections of high-volume arterials that exhibit a high frequency of severe and fatal crashes.

Corridor safety studies are usually conducted using a team approach. The corridor team is normally comprised of at least the following representatives:

• District Safety Engineer.
• District Media Specialist.
• County Maintenance Manager or designee.
• Representative of State or local police responsible for enforcement on the corridor.
• Local government representative.

Additional team members may also include the District Traffic Engineer, Local Emergency Medical Services (EMS) coordinator, a Metropolitan Planning Organization (MPO) representative, and a highway design representative.

Once a corridor has been identified for a study, the Safety Engineer and the District Media Specialist should perform an analysis of the crash data along the corridor to identify crash patterns that can be addressed by low-cost countermeasures and education/enforcement actions. All cluster lists need to be reviewed to identify specific locations within the corridor that appear on one or more of the cluster lists. It is anticipated that right turn in-right turn out turn limitations at stop-controlled intersections will be a significant countermeasure to consider on the multi-lane corridors.

After the crash analysis is completed, the corridor safety team is convened to review and discuss the crash analysis, findings, and safety concerns along the corridor from each member's perspective. The team then conducts a field review of the corridor, usually in one or two vehicles, to review areas of concern defined from the crash analysis and team discussions and any other safety aspect identified during the field review. The team then reconvenes and reaches consensus on a set of countermeasures and initiatives that have strong potential to reduce future severe crashes.

The District Safety Engineer and the District Media Specialist take the results of the team field review meeting and prepare a cost estimate and an assessment of the probable safety impacts and cost-effectiveness of implementing the recommended improvements. A brief report and tentative implementation schedule are prepared and used for programming consideration of cost-effective improvements.

After the countermeasures have been identified and approved by the agencies involved, staged and coordinated implementation of the recommendations begins. The team performs oversight and monitors the implementation activities to insure that substantive safety progress along the corridor is being made.

The corridors where 3E improvements should be considered are summarized in Table 28. Since the corridor approach is new to the State DOT, a pilot effort of three corridors will be initiated. The Executive Committee will evaluate the pilot. It if considered beneficial, the pilot will be expanded to the remaining corridors, incorporating lessons learned from the pilot.

Key Implementation Steps

The key steps necessary to fully implement this initiative and realize the safety benefits of the improvements, the organizations responsible for each key step, and the schedule to fully implement this activity are shown in Table 29.

10. Municipal-Wide 3E Improvements in Municipalities with High Frequencies of Severe Intersection Crashes

Description

The State DOT has identified 4 cities with the largest number of intersection fatalities over the past 6 years though crash data analysis. The purpose of this countermeasure is to identify a mid-size pilot city and initiate municipal-wide 3E approach, with an objective to reduce city intersection fatalities by a minimum of 10 percent using a combination of low-cost infrastructure improvements and targeted education and enforcement strategies beyond those that may be implemented in other systematic countermeasure deployments.

The effort begins with a preliminary meeting with city officials to determine interest in initiating a comprehensive intersection safety initiative. If interested, a thorough "cleaning up" of the crash data for intersection crashes on State and local roads within the city area is completed such that clusters of crashes at the same intersection can be accurately combined. After the data is cleaned, participants conduct a thorough analysis of the crash characteristics in the city, with the particular goal of understanding the problems that need to be addressed and relating the patterns to potential countermeasures. A city-wide multi-disciplinary team is then formed to review the crash analysis, discuss the intersection safety problems in the city, jointly field review the selected problem intersections to gain personal and group consensus of the major safety issues, and collectively develop an overall set of 3E countermeasures to improve safety in the city. After the countermeasures have been identified and approved by the agencies involved, staged and coordinated implementation of the recommendations begins. The team performs oversight and monitors the implementation activities to insure that substantive safety progress is being made.

The cities where 3E improvements should be considered are summarized in Tables 30 and 31. Since the city-wide 3E approach is relatively new to the State DOT, the pilot program will be closely monitored by the Executive Committee. The pilot will be evaluated by the Executive Committee, and, if considered beneficial, may be expanded to additional cities, incorporating lessons learned. If not beneficial, the Executive Committee can terminate or redirect the efforts.

11. Roundabouts

Description

Major improvements such as the construction of roundabouts require careful individual intersection analysis and are not appropriate to consider for systematic deployment. These major physical improvements have longer-term benefits since their expected lives may be 30 years or longer (as compared to about 10 years for signs and traffic signals). In addition, the effectiveness of these improvements to potentially reduce the number of crashes at a location is greater than lower-cost improvements. For example, the installation of roundabouts is expected to reduce severe intersection crashes by 90 percent. However their high initial costs prevent them from being considered for systematic deployment. In addition, significant factors such as available right of way, environmental issues, cost differentials between alternate major improvement types, and traffic operations will have an impact on choosing them as the optimum improvement type. As a result, these improvements are best suited to consider at intersections with the highest number of crashes.

Roundabouts are usually the most effective countermeasures in terms of reducing future crash potential; however, the high cost of construction significantly reduces the attractiveness of pursuing them. The expected rate of return in terms of lived saved per dollar invested is low compared to improving large numbers of intersections with lower-cost countermeasures. This is particularly the case when funding for safety is constrained and the objective is to reduce the maximum number of fatalities and incapacitating injuries possible with the available funds.

While intersections with the highest number of state-wide crashes will be considered as candidates for implementing systematic low-cost countermeasures as described earlier in the plan, these intersections also will be considered candidates for roundabout construction (where the CRF is 0.90 for fatalities and incapacitating injuries). Candidate intersections for roundabouts are shown in Table 32.

It is estimated that three roundabouts will be implemented during the time frame of this initiative, two at State, rural, stop-controlled intersections and one at State, rural, signalized intersections. The estimated annual reduction in crashes from these improvements is 32 crashes, 4 incapacitating injuries, and 0.36 fatalities.

Key Implementation Steps

The key steps necessary to fully implement this initiative and realize the safety benefits of the improvements, the organizations responsible for each key step, and the schedule to fully implement this activity are shown in Table 33.

⁴ Source: Federal Highway Administration, Informational Report on Lighting Design for Midblock Crosswalks, FHWA-HRT- 08-053 (Washington, DC: April 2008).

⁵ Institute of Transportation Engineers, Toolbox of Countermeasures and Their Potential Effectiveness to Make Intersections Safer, (Washington, DC: April 2004), http://www.ite.org/library/IntersectionSafety/toolbox.pdf.