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Intersections

Intersection Safety Action Plan

Sample Plan

June 2006

Prepared for:

Federal Highway Administration
Office of Safety

Prepared by:

Science Applications International Corporation
1710 SAIC Drive
McLean, VA 22102

A Note to the Reader – How to Use This Plan

Approximately 21 % of all traffic crash fatalities in the nation occur at intersections. If the national goal of reducing the fatality rate to no more than 1.0 death per one hundred million vehicle miles traveled is to be achieved, substantive reductions in intersection fatalities will have to occur. Traditionally, safety improvement programs have concentrated on addressing the highest crash locations in the State. Safety improvements are implemented at these locations each year, and for the most part, significant reductions of crashes have occurred. But from a statewide perspective, the number of improvements implemented is relatively small and reductions in deaths and serious injuries are almost negligible. Because traditional safety improvement programs effectively address a number of high-crash locations, they need to continue. In order to meet the national goal, states must expand their efforts, systematically applying low-cost, cost-effective improvements at a large number of locations with documented crash histories.

This Sample Intersection Safety Action Plan provides guidance, at a state level, on how to identify and systematically deploy cost-effective, publicly acceptable safety strategies that will result in a substantial statewide reduction of intersection fatalities and serious injuries. Although the Sample Plan was developed for a statewide condition, it can easily be adapted and applied for use on a regional or MPO area basis. The features of the Sample Plan are highlighted below.

The main text of the Sample Plan is written as if it was a complete plan authored by a state. “Notes to the Reader” are included to provide additional insight on important components of the Plan and special conditions or factors that need careful consideration when developing an actual Plan.
The Sample Plan has four major components: (1) intersection crash overview; (2) goal establishment; (3) approach to strategy selection and data analysis; and (4) strategy deployment levels and characteristics (e.g., costs, safety impacts).
The Sample Plan uses hypothetical data for a ‘typical’ moderate size state (1,003 total fatalities in 2003 of which 240 occurred at intersections) and uses some intersection fatality crash relationships extracted from the Fatality Analysis Reporting System (FARS) data base.
Almost every state should be capable of performing the majority of the data analyses in this Sample Plan with their own crash data and without any system upgrade or changes.
A “stretch” goal was established in the Sample Plan, along with a number of strategies and their levels of deployment needed to achieve the goal. A large number of strategies also were incorporated to provide a “shopping list” of potential strategies for states to consider. States have the flexibility of establishing whatever goal they desire to pursue and the number and deployment levels of strategies they intend to consider to achieve the goal.
Traditionally, a state will look at high-crash locations and determine a course of action for each location. In this plan, the strategies that will create the greatest cost-effective reductions in serious injuries and fatalities are identified first. Then the crash data system is accessed to determine at which locations strategies can be cost-effectively deployed.
The Sample Plan provides a process, using a benefit/cost (B/C) analysis, to determine the levels of deployment, statewide impact to the number of intersection crashes, and costs of improvement strategies.
This Sample Plan includes a discussion on the importance of statewide initiatives to improve safe driving behavior and their potential impact on intersection safety. It is important to document this tie-in if a State is also developing an overall strategic highway safety plan. The development of any intersection plan should be completely coordinated with the strategic plan. The intersection plan can be considered a subset of the strategic plan, or a detailed implementation plan for one of the key emphasis areas in the strategic plan.
This Sample Plan highlights important decisions and issues upper management must address if the effort is to be successfully implemented. Each state will have its own set of key decisions and directions that have to be effectively dealt with in order to be successful. These issues should be thoroughly identified, evaluated, and communicated to upper management, preferably with recommended courses of action.

States are encouraged to use this Sample Intersection Safety Action Plan as a guideline as they create their intersection goals, review their data, and identify improvement strategies. The content of this plan does not represent a Federal Highway Administration standard. States have the flexibility to design their Action Plans based on their individual needs and goals.

Executive Summary
Intersection Crash Overview
Multi-Vehicle Intersection Crash Characteristics
Pedestrian Crashes at Intersections
Single Vehicle Intersection Crashes
Speed Limits and Intersection Crash Severity
Traffic Way Flow Type vs. Serious Injuries and Fatalities
Illegal Driver Actions
Wet Pavement Conditions
Intersection Fatalities and Serious Injuries by Driver Age
Daylight vs. Nighttime Conditions
The Cost of Intersection Crashes
Summary of Potential Concerns
Intersection Goal
Approach
Strategy Selection
Data Analysis
Intersection Improvement Strategies
System-Wide Deployment of Low-Cost, Cost-Effective Improvements.
System-Wide Deployment of Medium- and High-Cost Improvements at High-Crash Locations.
Local Road Intersection Safety Initiatives
Corridor /Area-Wide Enforcement/Education/Engineering Initiative for Intersection Improvements
Corridor Enforcement/Education/Engineering Initiative
Area-Wide Enforcement/Education/Engineering Initiative
Safety and Cost Impacts of Intersection Improvement Strategies
Key Strategic Direction Issues
Goal Adjustment
Funding
Broad Policy Actions
Next Steps
Appendix A – Cost Effectiveness Data Analysis for Improvement Strategies
Appendix B – Crash Analysis for Corridor /Area-Wide Enforcement/Education/Engineering Improvement Strategies
Appendix C - Statewide Initiatives to Improve Safe Driving Behavior

Executive Summary

Note to the Reader: The purpose of the Executive Summary is to provide an overview of the entire plan. It builds the case for intersection improvement strategies and describes the estimated impacts of these strategies. It also highlights important decisions and issues which upper management must address if the effort is to be successfully implemented. Each state will have its own set of key decisions and directions that have to be effectively dealt with in order to be successful. These issues should be thoroughly identified, evaluated, and communicated to upper management, preferably with recommended courses of action.

Over the five-year period from 1999-2003 nearly 5,000 people lost their lives on highways within the State and, of these, nearly 1,200 died at intersections. In past years, a gradually improving infrastructure has helped keep the number of deaths from increasing, but the growth in traffic volumes has counteracted any real reductions in fatalities. The Hazard Elimination Program has improved between 60 and 70 high-hazard locations each year. Approximately 50% of these high-hazard locations have been intersections.

In addition, education and enforcement initiatives to increase safety belt usage, reduce drinking and driving, and reduce aggressive driving and speeding have contributed to severe crash decreases. However, for the State to continue to have reductions in the number of statewide intersection deaths, other strategic safety efforts are needed.

This Action Plan concentrates on identifying those primarily infrastructure-related improvements that can substantively reduce intersection deaths. Two principles have been established to better ensure success of the plan:

Cost effectiveness in terms of crash reductions; and,
Substantial contribution to achieving the goal of reducing serious injuries and deaths associated with intersections.

Strategy identification and deployment information was extracted from four prime resources as follows:

NCHRP Report 500, Volume 5 (Addressing Unsignalized Intersection Collisions)
NCHRP Report 500, Volume 12 (Reducing Collisions at Signalized Intersections)
Signalized Intersections: Informational Guide, FHWA http://www.tfhrc.gov/safety/pubs/04091/index.htm
Roundabouts: An Informational Guide, FHWA http://www.tfhrc.gov/safety/00068.htm

Pedestrian safety is also a concern at intersections. Pedestrian strategies are incorporated in the plan’s discussions of a corridor approach to addressing intersection safety. In addition, a separate guideline on how to develop a pedestrian action plan similar to the intersection plan is under development by FHWA. It is important that these two initiatives be coordinated during the development process so that opportunities to improve pedestrian safety at intersections can be fully realized.

A goal of decreasing intersection fatalities and serious injuries from 961 in 2003 to 850 by 2010 is established for the State. The plan demonstrates that a reduction of more than 130 intersection fatalities and serious injuries annually (which exceeds the goal) can be achieved through the strategic application of a broad array of infrastructure improvements.

Note to the Reader: This “shopping list” of strategies demonstrates that a comprehensive approach can be taken to substantially impact severe intersection crashes. The approach also can be consolidated and simplified to a few key strategies to achieve the stated goal.

Funding. This plan estimates that the following resources will be required to fund the level of cost effective improvements needed to prevent over 130 intersection deaths and serious injuries annually by 2010:

Approximately $96 million for infrastructure intersection improvements on the State highway system.
Approximately $7.0 million for local government infrastructure intersection safety improvements.
$7.3 million per year for corridor and municipal-wide driver safety (behavioral) initiatives.

The plan also identifies a reduced level of effort and funding necessary to reach (rather than exceed) the State’s goal of an annual reduction of 111 intersection fatalities and serious injuries by 2010.

Broad Policy Actions. There are four areas where policy actions are needed to effectively implement the Plan.

Traditionally the Hazard Elimination Program has concentrated on addressing the highest crash locations in the State. Because this program results in a relatively small number of improvements, the reductions in statewide numbers of deaths and serious injuries are almost negligible. However, the State should also focus on carefully administered, systematic deployment of key low-cost improvements that can produce results of such a magnitude that the statewide numbers of targeted deaths and serious injuries can be reduced.
Widespread use of enhanced signs and marking systems and automated red light running enforcement - two strategies which are not being applied statewide - is important in attaining the intersection goal of reduced serious injuries and fatalities. It should be the State’s policy to implement these improvements as extensively and cost effectively as possible.
Historically, safety enhancements have been implemented by a number of agencies, each often working in isolation. Combining these independent entities into a team addressing specific corridor and area-wide intersection problems has the potential to yield synergistic results and dramatically improve safety. It would be desirable for the State DOT to take the lead to form multi-disciplinary teams and address the severe crash problems on two to three targeted corridors initially. Based on the experiences and successes of these first efforts, the concept can be expanded to remaining problem corridors and municipal-wide concerns.
Approximately 20% of all serious injuries and deaths at intersections occur off the State highway system. Realistically, improvements will not be extensively implemented on local roads unless Federal funds and technical assistance by the State DOT are extended to the counties and municipalities. The State should develop guidelines for when Federal funds can be made available to municipalities to fund safety improvements identified in this Plan.

In conclusion, a substantive reduction in fatalities and serious injuries at intersections can be achieved through the judicious application of select strategies. It will, however, require the DOT to: (1) invest a moderate level of funding for the strategies; and, (2) have the fortitude to initiate new directions and cost effective strategies.

Intersection Crash Overview

Note to the Reader: The purpose of this section is to provide a sense of the magnitude of intersection crashes. It lays the foundation for all other elements of the Plan and defines the characteristics of intersection crashes as much as possible so that specific conclusions regarding implementation of strategies can be made. This section orients a State’s crash data so that it can be associated with the strategies to be deployed to impact intersection crashes. For each characteristic, data can be presented in tabular format and then summarized. This sample plan uses hypothetical data for a “typical” moderate size State (1,003 total fatalities in 2003 of which 240 occurred at intersections) and uses some intersection fatality crash relationships extracted from the FARS data system.

Over the five-year period 1999 to 2003 highway fatalities, serious injuries, and crashes in the State have remained relatively stable with a very slight upward trend as shown in Table 1.

Table 1. Highway Fatalities, Serious Injuries, and Crashes

	1999	2000	2001	2002	2003
Fatalities	962	982	974	998	1,003
Serious Injuries	4,561	4,432	4,619	4,481	4,596
Reportable Crashes	98,762	97,561	99,213	100,415	100,312

Table 2 shows that intersection crashes which involve multiple vehicles, a single vehicle running off the road, or a vehicle striking a pedestrian are a substantial portion of the statewide crash problem. In 2003, these crashes accounted for approximately 17% of the statewide serious injuries and deaths and 40% of statewide crashes.

Table 2. 2003 Intersection Crash Characteristics

		Signalized Intersections			Unsignalized Intersections			Total
		Multi-Vehicle	Single Vehicle	Pedestrian	Multi-Vehicle	Single Vehicle	Pedestrian	Total
Urban	Fatalities	41	10	11	38	10	6	116
	Serious Injuries	120	30	34	114	30	18	346
	Reportable Crashes	17,000	1,700	300	8,000	1,000	200	28,200
Rural	Fatalities	11	6	1	100	5	1	124
	Serious Injuries	34	18	4	300	15	4	375
	Reportable Crashes	2,500	300	20	8,000	1,000	20	11,840

Over this five-year period intersection deaths and serious injuries have remained relatively constant even though vehicular miles traveled (VMT) have increased, as shown in Table 3.

Table 3. Intersection Deaths and Serious Injuries

	1999	2000	2001	2002	2003
Intersection Deaths and Serious Injuries	960	965	970	950	961
VMT (Multiplied by 100 Million)	587	608	628	647	667

There are two primary factors responsible for this stability:

A Gradually Improving Infrastructure. The Hazard Elimination Program has improved between 60 and 70 high-hazard locations each year, approximately 50% of which are intersections.
Safer Drivers. Safety belt usage has climbed from 68% in 1999 to 75% in 2003. In addition, the passage of driving under the influence (DUI) legislation in 1999, which lowered the blood alcohol concentration (BAC) level from 0.10 to 0.08, has been a deterrent to drinking and driving.

Because this Plan addresses both signalized and unsignalized intersection crashes, the crash problem needs to be analyzed from a road ownership and an urban/rural perspective. These elements have a profound influence on the application of many of the strategies available to reduce intersection crashes. The distribution of 2003 intersection crashes by these factors and severity is indicated in Table 4. The percentage of fatalities in intersection crashes by road ownership is shown in Table 5 (see the next page).

Note to the Reader: For purposes of this example, it is assumed that the crash data system is not effectively tied into the highway infrastructure data system such that those intersections with zero crashes in the five-year study period can be identified. In addition, it is assumed that the exposure, expressed in average annual daily traffic (AADT) volumes, cannot be determined on a given intersection basis and intersection crash rates per million entering vehicles cannot be ascertained. While long-range efforts may be underway in a number of States to close these gaps, this analysis will rely on data emanating solely from the current crash data system.

Table 4. Distribution of 2003 Crashes by System Ownership

	Signalized Intersections				Unsignalized Intersections
Principal Route	Number of Intersections with Crashes	Crashes	Serious Injuries	Fatalities	Number of Intersections with Crashes	Crashes	Serious Injuries	Fatalities
Rural State/State Highways	500	2,400	40	14	3,000	6,020	210	70
Rural State/Local Highways	Unknown	400	14	4	Unknown	1,500	54	18
Rural Local/Local Highways	Unknown	20	2	0	Unknown	1,500	55	18
Urban State/State Highways	2,000	14,000	120	38	700	6,200	90	30
Urban State/Local Highways	Unknown	4,000	48	16	Unknown	1,500	30	10
Urban Local/Local Highways	Unknown	1,000	16	8	Unknown	1,500	42	14
Total		21,820	240	80		18,220	481	160

Note: The “Number of Intersections with Crashes” is shown as “Unknown” in the above table for State/Local and Local/Local intersections due to the inability of the crash data system to properly locate crashes off the State highway system (i.e. police officers may refer to the same intersection by different names on traffic crash reports).

Table 5. Percentage of 2003 Fatalities by System Ownership

	Signalized Intersections – Percentage of Total Intersection Deaths	Unsignalized Intersections – Percentage of Total Intersection Deaths	Total Percentage
Rural State/State Intersection	6	29	35
Rural State/Local Intersection	2	7	9
Rural Local/Local Intersection	0	7	7
Urban State/State Intersection	16	13	29
Urban State/Local Intersection	7	4	11
Urban Local/Local Intersection	3	6	9

Table 4 indicates that the highest number of intersection crashes occurs at urban state/state signalized intersections (14,000). However, Table 5 indicates that the highest percentages of fatalities occur at rural state/state unsignalized intersections (29%) and urban state/state signalized intersections (16%).

Multi-Vehicle Intersection Crash Characteristics

The information from Table 2 indicates that for both signalized and unsignalized intersections, the most common problem is multi-vehicle crashes. Further analysis of these crashes leads to a better understanding of the crash problem and the types of strategies that may be successful.

The distribution of multi-vehicle serious injuries and fatalities by type of intersection is shown in Table 6.

Note to the Reader: Most crash data systems capture the type of multi-vehicle crash. However, some crash data systems also capture vehicle movements. With these systems it is possible to obtain further information about the predominant angle crashes that occur at intersections. Rather than lumping all angle crashes together, a State may prefer breaking out left turn and right turn crashes separately.

Table 6. 2003 Intersection Multi-Vehicle Crash Type Fatalities and Serious Injuries by Intersection Category

	Angle (Major Road and Side Street Vehicle)	Angle (Two Opposing Major Road Vehicles)	Angle (Other)	Head-On	Rear-End	Opposing Flow Sideswipe	Same Direction Sideswipe
Signalized (Urban)	119	33	1	4	3	1	0
Signalized (Rural)	31	11	0	1	1	0	1
Unsignalized (Urban)	112	30	2	4	3	1	0
Unsignalized (Rural)	296	80	2	12	8	1	1
Total	558	154	5	21	15	3	2

The highest incidents of multi-vehicle intersection crashes involve angle crashes. The predominant angle crash type involves a major road and side street vehicle. This is followed by crashes involving two opposing major road vehicles, where for the most part, one vehicle turns left across the path of the opposing vehicle.

Pedestrian Crashes at Intersections

Pedestrian crash information can be found in Table 2 of this Plan. The data indicate that pedestrians are a primary concern at both urban signalized and unsignalized intersections. Table 2 also shows that there is a minimal pedestrian crash problem at rural intersections.

Single Vehicle Intersection Crashes

Single vehicle intersection crash information can be found in Table 2 of this Plan. Single vehicle crashes are relatively minimal in comparison to the multi-vehicle crashes that occur at intersections. These single vehicle crashes are relatively uniformly distributed in urban and rural areas, and under signalized and unsignalized conditions. While the crash data does not yield information on the underlying causes of these crashes, it is believed that many of them occur due to inattentive driving or loss of control when the driver must react to an unanticipated condition occurring in the intersection.

Speed Limits and Intersection Crash Severity

Table 7 shows that the severity of crashes increases as the speed limit on the major road increases.

Table 7. 2003 Major Road Speed Limit vs. Injury Severity

	Signalized Intersections			Unsignalized Intersections
Major Road Speed Limit	Total Crashes	Total Serious Injuries and Fatalities	Fatalities and Serious Injuries per 100 Crashes	Total Crashes	Total Serious Injuries and Fatalities	Fatalities and Serious Injuries per 100 Crashes
30 mph and below	2,000	20	1.0	2,000	35	1.7
35 mph	6,000	70	1.2	2,000	45	2.2
40 mph	6,000	80	1.3	2,000	55	2.7
45-50 mph	6,000	100	1.6	2,000	65	3.2
55 mph and above	1,820	50	2.7	10,220	441	4.3

Note that there are fewer total crashes at high-speed signalized intersections (due to the existence of fewer such intersections on high-speed roads), but the percentage of fatalities and serious injuries at signalized intersections is 2.7 times greater for 55mph and above speed limit approach intersections compared to 30mph or less approaches.

Traffic Way Flow Type vs. Serious Injuries and Fatalities

Table 8 shows serious injuries and fatalities for undivided and divided roadways.

Table 8. 2003 Serious Injuries and Fatalities by Type of Intersection

Type of Intersection	Undivided	Divided
Signalized	130	170
Unsignalized	470	150

Note: There are 20 “unknown or other” intersection types for signalized intersections and 21 for unsignalized intersections that are not shown in the above table.

Illegal Driver Actions

Table 9 shows that illegal driver actions play a role in many severe crashes at intersections. Three concerns are as follows:

Fatalities and serious injuries caused by drivers who violated a traffic control device or lost control due to moving violations - these include speeding, reckless driving, and failure to obey a traffic control device.
Alcohol-related fatalities and serious injuries
Fatalities and serious injuries where drivers and/or occupants were unbelted

Table 9. 2003 Serious Injuries and Fatalities Involving Illegal Driving Actions

		Signalized Intersections	Unsignalized Intersections
Fatalities and Serious Injuries Involving Illegal Driving	Total	160	307
Fatalities and Serious Injuries Involving Illegal Driving	% of All Intersection Serious Injuries and Fatalities that Involved Illegal Driving Actions	50	48
Alcohol-Related Fatalities and Serious Injuries	Total	90	179
Alcohol-Related Fatalities and Serious Injuries	% of All Intersection Fatalities and Serious Injuries Involving Alcohol	28	28
Unbelted Driver and Occupant Fatalities and Serious Injuries	Total	200	441
	% of All Intersection Fatalities and Serious Injuries Where Vehicular Occupants Were Unbelted (Note that these numbers do not include pedestrian fatalities and serious injuries as shown in Table 2)	74	72

In addition to illegal driving actions, drivers who are distracted, fatigued, inattentive, or who fall asleep are also considered factors in intersection crashes. However, these factors seem to be underreported in the crash data system.

Wet Pavement Conditions

Table 10 shows that 16-17% of the crashes at intersections occur on wet pavements. Intersections that have a large number and proportionately higher rate of wet pavement crashes (larger than 17%) may have a slippery pavement condition which contributes to higher crash frequencies.

Table 10. 2003 Wet Pavement Crashes

Category	Signalized Intersections	Unsignalized Intersections
Wet	3,742	3,000
Total	21,820	18,220
Wet/Total Ratio	0.17	0.16

Intersection Fatalities and Serious Injuries by Driver Age

Table 11 shows that drivers aged 16 to 18 and 75 and over have a disproportionately high number of fatal and serious injury crashes (24.1% combined compared to 15.1% of these-aged drivers in the traffic stream, as shown in the table) when they pull out from a stop sign. This same type of distribution is not shown in the table but occurs for the other angle crash type involving two opposing major road vehicles where one vehicle turns left across the path of the other vehicle. The turning driver has the higher crash distributions at the younger and older ends of the age spectrum. Younger drivers may have difficulty in determining safe gaps because of inexperience and higher risk taking. Older drivers may have problems associated with reduced vision capabilities. (It is noted that this information does not provide evidence as to which vehicle was at-fault in the crashes.)

Table 11. Driver Age Distribution in 2003 Angle Crashes at Unsignalized Intersections

Age	Drivers Pulling Out from Stopped Approach (Driver Distribution %)	Major Road Drivers (Driver Distribution %)
16	5.8	3.5
17	5.0	3.5
18	4.2	3.4
19-21	7.9	7.8
22-25	9.1	10.6
26-35	16.8	19.2
36-44	16.2	18.5
45-54	11.8	13.3
55-65	8.7	10.1
66-74	4.6	4.7
75-80	4.4	2.2
>80	4.7	2.5
Unknown	0.8	0.7
TOTAL	100.0	100.0

Daylight vs. Nighttime Conditions

When considering light conditions, only one reported crash condition is considered preventable by applying lighting – “Dark – No Street Lights”. The other crashes either occurred in the day, in dark conditions with existing street lights, or when the light condition was unknown. Table 12 shows the extent of the crashes that occurred in different lighting conditions.

Table 12. 2003 Intersection Crashes and Light Condition

	Signalized Intersections	Unsignalized Intersections
Daylight	13,800	11,620
Dark with Street Lights	3,800	2,000
Dark – No Street Lights	3,720	4,000
Unknown	500	600
TOTAL	21,820	18,220

Unlit intersections that have a high number of night crashes and a proportionally higher rate of night to total crashes than the statewide average for unlit intersections may benefit from street lighting.

The Cost of Intersection Crashes

The costs of intersection crashes may vary depending on specific factors involved. Two key measurements are needed in the upcoming analysis:

Average cost of specific crash types expressed in dollars. This is needed to determine if an improvement may be cost effective.
Expected deaths and serious injuries per 100 crashes that may be reduced for various crash types. This is needed to determine the extent to which an improvement helps achieve a serious injury and fatality goal.

The monetary costs of crashes are based upon FHWA cost estimates issued February 12, 2002 as noted below:

Fatality – $ 3,000,000.
Serious injury – $209,000.
Non-serious injury – $42,000.
Possible injury – $22,000.
Property damage – $2,300.

The FHWA injury estimates are based upon the abbreviated injury scale (AIS). Since the State’s definition of injury severity does not use the AIS, an interpolation of the FHWA estimates was made to coincide with the injury definitions used on the police crash report.

The average crash costs and death and serious injury rates for the major crash types were extracted from the crash data and the FHWA cost estimates were applied. The results are as follows.

Table 13. Average Crash Cost and 2003 Death/Serious Injury Rates

	Condition	Average Crash Costs ($000)	Deaths and Serious Injuries Per 100 Crashes
Signalized Rural	Angle (Major Road and Side Street Vehicle)	22	2.5
	Angle (Two Major Road Vehicles)	20	2.4
	Rear End	7	0.8
	All Crashes	18	2.3
	Pedestrian Crashes	Unknown	Unknown
Signalized Urban	Angle (Major Road and Side Street Vehicle)	18	2.2
	Angle (Two Major Road Vehicles)	16	2.1
	All Crashes	10	1.1
	Pedestrian Crashes	140	28.6
Unsignalized Rural	Angle (Major Road and Side Street Vehicle)	42	4.8
	Angle (Two Major Road Vehicles)	42	4.8
	Rear End (Major Road only)	10	1.1
	All Crashes	40	4.6
	Pedestrian Crashes	Unknown	Unknown
Unsignalized Urban	Angle (Major Road and Side Street Vehicle)	18	2.2
	Angle (Two Major Road Vehicles)	16	2.1
	All Crashes	16	2.0
	Pedestrian Crashes	130	26.6

Note: The “Unknown” shown in the rows for Pedestrian Crashes in this table is due to the relatively low number of pedestrian crashes, fatalities and serious injuries in rural areas (see Table 2).

Summary of Potential Concerns

Based on the data presented, the potential concerns regarding intersection fatalities and serious injuries are as follows.

Rural unsignalized intersections primarily on State highways. (Table 4)
Urban signalized intersections on State highways. (Table 4)
Multi-vehicle angle crashes involving major road and entering vehicles at urban and rural intersections. (Table 6)
Multi-vehicle angle crashes involving two major road vehicles at urban and rural intersections. (Table 6)
Pedestrian crashes in urban areas at both signalized and unsignalized intersections. (Table 2)
Intersections with higher speed limits on the major road (higher proportions of serious injuries and deaths). (Table 7)
Signalized and unsignalized physically divided intersections. (Table 8)
Intersections with a large and disproportionate number of wet pavement crashes. (Table 10)
Unlit intersections with a large and disproportionate number of night crashes. (Table 12)
Young and old drivers who have difficulty selecting safe gaps. (Table 11)
Illegal driving actions relating to speed, alcohol, and/or unbelted drivers and occupants. (Table 9)

Intersection Goal

Note to the Reader: The purpose of this section of the Plan is to clearly state the intersection goal. Discussion of the goal includes at least the following information: what data will be used, the proposed reduction levels and date by which the goal should be reached, and assumptions about future conditions. The goal should be measurable and expressed in terms of a statewide reduction of intersection fatalities, serious injuries, crashes, or any combination of these by a defined date. A “stretch” goal was established in the Sample Plan along with a number of strategies and their levels of deployment needed to achieve the goal. States have the flexibility of establishing whatever goal they desire.

After careful analysis of the data and a review of the accuracy of serious injury classifications, the combination of fatalities and serious injuries will be used as the intersection performance measure in the goal. The State has also adopted an overall safety goal of achieving a fatality rate of 1.0 fatality per 100 million vehicle miles traveled by 2008, which matches the national goal. Strategies identified in this plan to reduce intersection fatalities and serious injuries will help the State make progress toward the overall goal.

Recognizing that separate initiatives will be underway to increase safety belt usage and to reduce drinking and driving and aggressive driving (which will also reduce intersection deaths and serious injuries), this initiative will concentrate on primarily infrastructure-related strategies that can reduce intersection deaths and serious injuries.

Over the period 2003 to 2010, traffic volumes are expected to continue growing at a rate of three percent per year. Intersection entering volume rates are difficult to aggregate into a single overall rate. It is anticipated that over the next few years, the State will have the computer programming capability to sum entering intersection daily traffic volumes for all State intersection approaches at State-only intersections. The State should also be able to calculate an estimated volume for local highway approaches to State intersections based on the functional class of the local road. As a result, intersection crash rates in terms of crashes per million entering vehicles will be calculated and average and abnormal intersection crash rates can be determined for various types of intersections. When completed, an intersection crash rate goal will be incorporated into the plan. However, for current conditions, only crash data will be used in the goal.

The intersection goal is as follows:

Reduce the intersection serious injuries and deaths from 961 in 2003 to no more than 850 in 2010.

Approach

Note to the Reader: This section begins with a discussion of the sources of improvement strategies and the process by which strategies were chosen for consideration to help achieve the goal. A description of the strategies is then provided. The section ends with a summary of the data and analysis procedures used to quantify the impact of improvement strategies.

Strategy Selection

Preventing 111 intersection combined deaths and serious injuries each year is a challenge, particularly since the existing safety efforts only have been able to maintain the existing level of 961 annual serious injuries and deaths. New, effective strategies have to be skillfully deployed if reductions are to be achieved.

Information from the following reports was used in identifying promising strategies:

NCHRP Report 500, Volume 5 (Addressing Unsignalized Intersection Collisions) Strategies
- 17.1 A—Improve management of access near unsignalized Intersections
  - 17.1 A1—Implement driveway closures/relocations (T)
  - 17.1 A2—Implement driveway turn restrictions (T)
- 17.1 B—Reduce the frequency and severity of intersection conflicts through geometric design improvements
  - 17.1 B1—Provide left-turn lanes at intersections (P)
  - 17.1 B2—Provide longer left-turn lanes at intersections (T)
  - 17.1 B3—Provide offset left-turn lanes at intersections (T)
  - 17.1 B4—Provide bypass lanes on shoulders at T-intersections (T)
  - 17.1 B5—Provide left-turn acceleration lanes at divided highway intersections (T)
  - 17.1 B6—Provide right-turn lanes at intersections (P)
  - 17.1 B7—Provide longer right-turn lanes at intersections (T)
  - 17.1 B8—Provide offset right-turn lanes at intersections (T)
  - 17.1 B9—Provide right-turn acceleration lanes at intersections (T)
  - 17.1 B10—Provide full-width paved shoulders in intersection areas (T)
  - 17.1 B11—Restrict or eliminate turning maneuvers by signing (T)
  - 17.1 B12—Restrict or eliminate turning maneuvers by providing channelization or closing median openings (T)
  - 17.1 B13—Close or relocate “high-risk” intersections (T)
  - 17.1 B14—Convert four-legged intersections to two T-intersections (T)
  - 17.1 B15—Convert offset T-intersections to four-legged intersections (T)
  - 17.1 B16—Realign intersection approaches to reduce or eliminate intersection skew (P)
  - 17.1 B17—Use indirect left-turn treatments to minimize conflicts at divided highway intersections (T)
  - 17.1 B18—Improve pedestrian and bicycle facilities to reduce conflicts between motorists and nonmotorists (varies)
- 17.1 C—Improve sight distance at unsignalized intersections
  - 17.1 C1—Clear sight triangles on stop- or yield-controlled approaches to intersections (T)
  - 17.1 C2—Clear sight triangles in the medians of divided highways near intersections (T)
  - 17.1 C3—Change horizontal and/or vertical alignment of approaches to provide more sight distance (T)
  - 17.1 C4—Eliminate parking that restricts sight distance (T)
- 17.1 D—Improve availability of gaps in traffic and assist drivers in judging gap sizes at unsignalized intersections
  - 17.1 D1—Provide an automated real-time system to inform drivers of the suitability of available gaps for making turning and crossing maneuvers (E)
  - 17.1 D2—Provide roadside markers or pavement markings to assist drivers in judging the suitability of available gaps for making turning and crossing maneuvers (E)
  - 17.1 D3—Retime adjacent signals to create gaps at stop-controlled intersections (T)
- 17.1 E—Improve driver awareness of intersections as viewed from the intersection approach
  - 17.1 E1—Improve visibility of intersections by providing enhanced signing and delineation (T)
  - 17.1 E2—Improve visibility of the intersection by providing lighting (P)
  - 17.1 E3—Install splitter islands on the minor-road approach to an intersection (T)
  - 17.1 E4—Provide a stop bar (or provide a wider stop bar) on minor road approaches (T)
  - 17.1 E5—Install larger regulatory and warning signs at intersections (T)
  - 17.1 E6—Call attention to the intersection by installing rumble strips on intersection approaches (T)
  - 17.1 E7—Provide dashed markings (extended left edgelines) for major-road continuity across the median opening at divided highway intersections (T)
  - 17.1 E8—Provide supplementary stop signs mounted over the roadway (T)
  - 17.1 E9—Provide pavement markings with supplementary messages, such as STOP AHEAD (T)
  - 17.1 E10—Provide improved maintenance of stop signs (T)
  - 17.1 E11—Install flashing beacons at stop-controlled intersections (T)
- 17.1 F—Choose appropriate intersection traffic control to minimize crash frequency and severity
  - 17.1 F1—Avoid signalizing through roads (T)
  - 17.1 F2—Provide all-way stop-control at appropriate intersections (P)
  - 17.1 F3—Provide roundabouts at appropriate locations (P)
- 17.1 G—Improve driver compliance with traffic control devices and traffic laws at intersections
  - 17.1 G1—Provide targeted enforcement to reduce stop sign violations (T)
  - 17.1 G2—Provide targeted public information and education on safety problems at specific intersections (T)
- 17.1 H—Reduce operating speeds on specific intersection approaches
  - 17.1 H1—Provide targeted speed enforcement (P)
  - 17.1 H2—Provide traffic calming on intersection approaches through a combination of geometrics and traffic control devices (P)
  - 17.1 H3—Post appropriate speed limit on intersection approaches (T)
- 17.1 I—Guide motorists more effectively through complex intersections
  - 17.1 I1—Provide turn path markings (T)
  - 17.1 I2—Provide a double yellow centerline on the median opening of a divided highway at intersections (T)
  - 17.1 I3—Provide lane assignment signing or marking at complex intersections (T)
NCHRP Report 500, Volume 12 (Reducing Collisions at Signalized Intersections) Strategies
- 17.2 A Reduce frequency and severity of intersection conflicts through traffic control and operational improvements
  - 17.2 A1 Employ multiphase signal operation (P, T)
  - 17.2 A2 Optimize clearance intervals (P)
  - 17.2 A3 Restrict or eliminate turning maneuvers (including right turns on red) (T)
  - 17.2 A4 Employ signal coordination along a corridor or route (P)
  - 17.2 A5 Employ emergency vehicle preemption (P)
  - 17.2 A6 Improve operation of pedestrian and bicycle facilities at signalized intersections (P, T)
  - 17.2 A7 Remove unwarranted signal (P)
- 17.2 B Reduce frequency and severity of intersection conflicts through geometric improvements
  - 17.2 B1 Provide/improve left-turn channelization (P)
  - 17.2 B2 Provide/improve right-turn channelization (P)
  - 17.2 B3 Improve geometry of pedestrian and bicycle facilities (P, T)
  - 17.2 B4 Revise geometry of complex intersections (P, T)
  - 17.2 B5 Construct special solutions (T)
- 17.2 C Improve sight distance at signalized intersections
  - 17.2 C1 Clear sight triangles (T)
  - 17.2 C2 Redesign intersection approaches (P)
- 17.2 D Improve driver awareness of intersections and signal control
  - 17.2 D1 Improve visibility of intersections on approach(es) (T)
  - 17.2 D2 Improve visibility of signals and signs at intersections (T)
- 17.2 E Improve driver compliance with traffic control devices
  - 17.2 E1 Provide public information and education (T)
  - 17.2 E2 Provide targeted conventional enforcement of traffic laws (T)
  - 17.2 E3 Implement automated enforcement of red-light running (cameras) (P)
  - 17.2 E4 Implement automated enforcement of approach speeds (cameras) (T)
  - 17.2 E5 Control speed on approaches (E)
- 17.2 F Improve access management near signalized intersections
  - 17.2 F1 Restrict access to properties using driveway closures or turn restrictions (T)
  - 17.2 F2 Restrict cross-median access near intersections (T)
- 17.2 G Improve safety through other infrastructure treatments
  - 17.2 G1 Improve drainage in intersection and on approaches (T)
  - 17.2 G2 Provide skid resistance in intersection and on approaches (T)
  - 17.2 G3 Coordinate closely spaced signals near at-grade railroad crossings (T)
  - 17.2 G4 Relocate signal hardware out of clear zone (T)
  - 17.2 G5 Restrict or eliminate parking on intersection approaches (P)

Note: For the strategies in these two NCHRP Report 500 volumes, “P” means proven, “T” tried, and “E” experimental.

Signalized Intersections: Informational Guide, FHWA http://www.tfhrc.gov/safety/pubs/04091/index.htm
Roundabouts: An Informational Guide, FHWA http://www.tfhrc.gov/safety/00068.htm

The implementation of potential strategies must be cost effective and lead to a reduction of intersection serious injuries and fatalities toward meeting the goal. The following four opportunity areas are identified as potentially the most productive toward achieving the intersection crash goal. These areas are discussed in detail in the following section of this Plan on Intersection Improvement Strategies.

System-wide deployment of low-cost, cost effective improvements.
System-wide deployment of medium and high-cost improvements at high-crash intersections.
Corridor and area-wide enforcement/education/engineering intersection initiative.
Local road intersection safety initiative.

Data Analysis

The following summarizes the data and procedures used to quantify the impacts of improvement strategies. More detailed information is provided in the improvement strategy section of this Plan.

The crash data system is used to identify potential candidate locations with appropriate crash histories for each of the opportunity areas above. The crash data is merged with the roadway data files and the traffic volume files to provide more insight into the characteristics of the problem. However, the relationships of databases, with the exception of crash locations on State highways, have not been fully established and use of data from these systems is not feasible at this time.
A five-year crash history (1999 to 2003) has been used in all of the calculations in the analyses.

A benefit/cost (B/C) calculation is used to determine the threshold level of crashes to justify implementing an improvement. The effectiveness of various strategies, where available, was determined from information in the following reports: NCHRP Report 500, Volume 5 (Addressing Unsignalized Intersection Collisions); NCHRP Report 500, Volume 12 (Reducing Collisions at Signalized Intersections); FHWA’s Signalized Intersections: Informational Guide; and, FHWA’s Roundabouts: An Informational Guide. Other reliable sources of countermeasure effectiveness information can also be used where and when appropriate. Where ranges of effectiveness are available, the midpoint was used in the calculations.

The NCHRP 500 Reports contain strategies that are experimental as well as tried and proven. Once the B/C threshold is set (2.0 is used here), the crash data system is searched to identify candidate locations that meet or exceed the threshold. The number of candidate locations that can ultimately be improved is estimated. (Subsequent field reviews and design developments may render some of the candidate sites inappropriate for improvements.)
A statewide estimate of the impact (i.e. reduction in serious injuries and fatalities) of implementing each improvement type is calculated.
The impacts of all improvement types are summed to determine if the overall effort is adequate to achieve the goal (i.e. 111 fewer annual serious injuries and fatalities at intersections by 2010).

Intersection Improvement Strategies

Note to the Reader: This portion of the Plan provides detailed information on each strategy proposed to be deployed. Traditionally, a state will look at high-crash locations and determine a course of action for each location. In this plan, the strategies that will create the greatest cost-effective reductions in serious injuries and fatalities are identified first. Then the crash data system is searched to determine locations where these strategies can be deployed cost effectively. A statewide assessment of the costs to deploy and impacts in terms of the goal (fatalities and serious injuries prevented) is made for each strategy

A large number of strategies have been incorporated to provide a “shopping list” of potential strategies for states to consider. Strategies were selected based upon their expected potential to reduce serious injuries and fatalities and their capacity to be deployed in a cost-effective manner. States don’t have to embrace the entire range of strategies.

Information presented in this section may vary by strategy, but each strategy should attempt to contain: a detailed description of the strategy; the conditions under which the strategy will be applied; levels of deployment; estimated costs; estimated reduction levels in intersection fatalities and serious injuries; and cost-effectiveness. In this Sample Plan, strategies are grouped into categories for ease of presentation and discussion. Information is provided in both tabular and written format.

System-Wide Deployment of Low-Cost, Cost-Effective Improvements

Three types of low-cost, system-wide improvements are proposed.

Enhanced Sign and Marking Systems at Unsignalized Intersections. This set of improvements is targeted to unsignalized intersections on State highways with sufficient crash histories such that implementation of the improvement will likely be cost-effective (signalized intersections are covered in #2 below). They can be applied in both urban and rural settings, and are most appropriate in isolated conditions. These passive warning systems, sometimes in combination with active warning beacons, are designed to: (1) slow down excessive speeding on major road approaches; (2) heighten the alertness of all entering drivers to the approaching intersection; (3) encourage stopped drivers to scan the intersection properly before entering; and, (4) encourage stopped vehicles to stop at the correct approach location. A team including representatives of the State DOT, university, FHWA, and a human factors expert will analyze the crash characteristics, identify the most promising enhanced sign/marking combinations, and develop the criteria for deployment. The team also will identify a set of enhanced signs and marking improvements (compliant with the MUTCD) that have the potential to yield significant safety benefits and will propose installation at approximately five to 10 problem locations at which these improvements can be evaluated to determine safety impact prior to considering system-wide deployment.

The estimated unit cost of this improvement is $3,000 per intersection. The actual effectiveness of this strategy is unknown, however, it is conservatively estimated that the improvement will reduce overall intersection crashes by 15%. (Note: States may use other effectiveness rates for this and other strategies based on existing information, such as the NCHRP Report 500 Volumes 5 and 12 or other viable sources, experience and/or judgment.) Urban and rural intersections will be evaluated separately because the severity of crashes in rural areas is much higher than in urban areas.

Minor Traffic Signal Enhancements. This set of improvements can be applied in both urban and rural areas, but are predominantly found in urban areas. The system of improvements includes signing and marking upgrades on signalized intersection approaches, signal upgrades, and application of advanced detector system technology where warranted, to: reduce high-end approach speeds and heighten driver alertness; increase the conspicuity of signal heads (e.g., increased size of lens, heads centered over the traffic lanes, back plates, wattage, etc.); accommodate pedestrians; and, provide safe clearance times between phases. The estimated average unit cost of these improvements is $30,000 per intersection and will vary from intersection to intersection depending on the base conditions. The actual effectiveness of these improvements is unknown, however, it is conservatively estimated that the combined improvements will reduce overall intersection crashes by 15%. (Note: Some signal-related strategies have effectiveness rates as high as 30-60%. States should consult available sources, such as the NCHRP Report 500 Volumes 5 and 12, for more information.) Urban and rural intersections will be evaluated separately because the severity of crashes in rural areas is much higher than in urban areas.
Stop Approach Enhancements. This set of improvements is limited to rural unsignalized intersections which have a substantial crash history associated with drivers running a stop sign (as determined from the causal factors reported in the police crash report and included in the crash data system). The improvements include:
1. Advance intersection and traffic control warning signs, oversize signs, “doubled up” warning signs, and warning beacons;
2. Transverse rumble strips and/or pavement markings on the stop approach designed to attract the attention of approaching motorists of the upcoming intersection (rumble strips should only be applied in those rural settings that do not have adjacent or close dwellings due to noise issues);
3. Splitter islands to separate opposing traffic directions at the intersection and to provide for designated turning lanes;
4. “Pork Chop” islands for placement of right-of-way control signs more central in the approaching driver’s cone of vision; and,
5. Increasing the size or “doubling-up” of “STOP” signs and/or adding flashing beacons to “STOP” signs.
The estimated cost of these improvements is $25,000 per intersection. The estimated effectiveness is a 50% reduction in crashes involving vehicles that run stop signs.

Application of the above criteria to the crash data system yields the results shown in Table 14 on the next page. Appendix A provides a description of the cost effectiveness data analysis performed to produce this information.

Note to the Reader: States should consider including an appendix of data analysis work as part of their plans. Appendix A provides a description of the cost effectiveness data analysis performed to produce the information in Table 14. This data analysis process should be the same for all improvements discussed in the plan.

Table 14. Cost and Impact Summary – Low-Cost, Cost-Effective Improvements (Crash Data Systems That Can Locate Crashes by Specific Location on a Route)

Category	Threshold Crash Level (Five Years)	Number of Statewide Crash Intersections	Number of Targeted Five-Year Crashes in the Intersections	Estimated Number of Improvements	Construction Costs ($ Million)	Type of Crash Reduced	Annual Targeted Crash Reduction	Annual Serious Injury and Fatality Reduction
Enhanced Sign and Marking – Unsignalized Rural Intersections	5 crashes	880	8,400	800	2.4	Intersection	230	11
Enhanced Sign and Marking –Unsignalized Urban Intersections	10 crashes	350	6,000	300	0.9	Intersection	154	3
Rural Traffic Signal Minor Enhancements	15 crashes	35	450	30	0.9	Intersection	12	<1
Urban Traffic Signal Minor Enhancements	20 crashes	450	15,000	400	12.0	Intersection	400	4
Stop Approach Improvements at Rural Unsignalized Intersections	3 running stop sign crashes	48	200	36	0.9	Intersection (running stop signs)	15	1
Total					17.1		811	20

It can be seen that collectively, these low-cost improvements are projected to reduce intersection serious injuries and deaths by 20 on an annual basis and cost $17.1 million to implement.

Calculation Example in Table 14:

Enhanced Sign and Marking - Unsignalized Rural Intersections

8,400/5 x 800/880 x 0.15 =229 annual crashes reduced (230 used in Table)

(230/100) x 4.6 (from Table 13) =10.58 annual fatalities and serious injuries reduced per year (rounded to 11 in Table)

System-Wide Deployment of Medium- and High-Cost Improvements at High-Crash Locations

Note to the Reader: For each strategy the threshold crash criteria selected takes into consideration: (1) the likelihood that future crash problems would exist if no actions are taken; and, (2) the probability that the strategy can be implemented at the intersection cost-effectively. For example, lighting unlit intersections with five or more night crashes in five years and where the proportion of night – not lighted to total crashes is greater than 0.40 at a cost of $10,000 per intersection, will yield night crash reduction benefits that are at least twice that of the construction cost of lighting over the life of the improvement. States would need to select criteria based on their crash conditions.

Strategies that are medium or high-cost also are possible for system deployment. Because of higher costs, these deployments are considered only at high-crash intersections that have crash types mitigated by the strategies. A review of the medium- to high-cost strategies in NCHRP Report 500 Volumes 5 and 12, coupled with the crash analysis, yields the following improvements and crash types for further analysis (in no particular order of importance or effectiveness).

Sight distance improvements and/or dynamic warning systems at those unsignalized intersections having a substantial number of angle crashes (for example, five or more in five years) involving a major road vehicle and an entering vehicle from the side street. Since the crash data system does not provide information on the available sight distance at the intersection, field reviews will be necessary. A dynamic intersection warning system will be considered where it is determined that sight distance improvements will not significantly improve safety.
Left turn lanes at those unsignalized intersections having a substantial number of angle (left turning) crashes (for example, eight or more in five years) involving two major road opposing vehicles, one turning across the path of the other, or rear-end crashes (for example, eight or more in five years). Major road rear end crashes have been added to the analysis. A field review will be necessary to determine if the installation of left turn lanes is feasible and appropriate. It is desirable to offset opposing left turn lanes to increase visibility of approaching vehicles.
Left turn exclusive phases and lanes if not available at those signalized intersections having a substantive number of angle (left turning) crashes involving two opposing major road vehicles, one turning across the path of the other. Major road rear end crashes have been added to the analysis. Again, it will be necessary to verify through a field review later to determine if the installation of left turn lanes and phases is feasible and appropriate.
Lighting at those unlit intersections with a high number of crashes (for example, five or more night crashes in five years) and where the proportion of night – not lighted to total crashes is greater than 0.40. The value of 0.40 was selected because it is above the mean (0.33) night to total crash rate for all statewide intersections.
Application of high-friction surfaces on high-speed approaches (where the speed limit is equal or greater than 40 mph) having a high number of crashes (for example, five or more wet pavement crashes in five years) and a proportion of wet pavement to total crashes of 0.25 or greater. A skid test must confirm that the pavement surface friction is less than desirable.
Pedestrian improvements (e.g., pedestrian signals, cross walks, traffic calming) at intersections that have a substantial pedestrian crash problem (for example, three or more pedestrian crashes in five years).
Roundabouts or other major geometric improvements such as the elimination of skewed approaches at those unsignalized intersections with high numbers of crashes (for example, 20 or more in five years).
Automated Red Light Running Traffic Signal Enforcement. This set of improvements is limited to municipal-wide application of photo-radar enforcement at signals that exhibit higher frequencies of crashes involving running red lights. Implementation requires passage of State legislation. Municipalities having high numbers of signalized intersection crashes (100 or more signalized intersection crashes) would be candidates. The estimated average cost is $500,000 per municipality and consists of a ‘floating’ photo radar system that can be used at all of the intersections exhibiting high crash rates. The estimated effectiveness is a 15% reduction in municipal-wide red light running crashes. (Note: States may use other, higher effectiveness rates if they can be verified in NCHRP Report 500 or other reliable sources, knowledge and/or experience.)

Application of the above criteria to the crash data system yields the results shown in Table 15 (on the next page). These medium-and-high-cost improvements are projected to reduce intersection serious injuries and deaths by 40 on an annual basis and cost $63.2 million to implement.

Note: The estimated effectiveness values for each strategy are shown in parentheses in the “Annual Number of Crash Types Reduced (Estimated Effectiveness)” column of the table. Also, the determination of Annual Reduction in Serious Injuries and Fatalities in Table 15 is derived from the “Deaths and Serious Injuries per 100 Crashes” information in Table 13, except for night crashes and wet pavement crashes which were determined separately from available information in the crash data system.

Calculation example for Table 15 (on page 24)

Sight Distance Improvements or Dynamic Warning Systems

(1,200/5) x 0.20 =48 annual crashes reduced

(48/100) x 4.6 (from Table 13) =2.2 annual reduction in fatalities and serious injuries (shown as 2 in Table)

Table 15. Cost and Impact Summary – Medium- and High-Cost Improvements at High-Crash Intersections

Category	Threshold Crash Level (Five Years)	Number of Clusters at or Above Threshold	Estimated Number Improved	Estimated Number of Targeted Five-Year Crashes in Clusters Improved	Type of Crash Reduced	Annual Number of Crashes Reduced (Estimated Eff.)	Annual Reduction in Serious Injuries and Death	Construction Costs ($ Million)
Sight Distance Improvements or Dynamic Warning Systems	5 angle crashes involving a major road and entering vehicle	200	150	1,200	Angle involving a major road and entering vehicle	48 (0.20)	2	15.0
Left Turn Lanes at Unsignalized Rural Intersections	8 angle crashes involving two opposing major road vehicles	40	32	300 angle 400 rear end	Angle involving two major road vehicles	25 angle (0.42) 60 rear end (0.75)	1 (angle) 1(rear end) 2 Total	9.6
Left Turn Phases and/or Lanes at Signalized Intersections	8 angle crashes involving two opposing major road vehicles	60	50	800 angle 800 rear end	Angle involving two major road vehicles	67 angle (0.42) 120 rear end (0.75)	2 (angle) 1(rear end) 3 Total	4.0
Lighting at Unlit Intersections	5 night crashes and a night/total crash ratio >0.40	80	60	480	Night crashes	38 (0.40)	2	0.6
High Friction Surfaces for Slippery Pavements	5 wet pavement crashes on >35mph approaches and a wet/total crash ratio >0.25	100	60	800	Wet pavement crashes	80 (0.5)	3	3.0
Pedestrian Improvements (Traffic Calming, Pedestrian Phases, Crosswalks, Refuge Islands)	3 pedestrian crashes	70	60	230	Pedestrian crashes	14 (0.3)	4	1.0
Roundabouts	20 crashes	60	40	1,120	Roundabouts	202 (0.9)	9	18.0
Automated Red Light Running Enforcement	500 signalized intersection crashes per municipality	30 munici-palities	24	44,000	Intersection (red light running crashes)	1,320 (0.15)	15	12.0
Total						1974	40	63.2

Local Road Intersection Safety Initiatives

Approximately one-fourth of all intersection crashes occur on local roads. The data for the local road system is not as accurate and complete as that for the State highway system but was used as an initial tool to identify potential municipalities and routes that have concentrations of targeted intersection crashes.

Since there are fewer crashes on local roads and they occur over a much larger road system, the level of concentration will be much less than that found on the State highway system. One general type of intersection strategy will be pursued on local roads as follows.

Basic and Enhanced Signing and Marking for Unsignalized Intersections. This initiative proposes to upgrade municipal-wide intersection signing and marking in those municipalities that have 25 or more local road intersection crashes at unsignalized intersections over a five-year period. The upgrade will bring the signs to the basic requirements in the 2003 MUTCD and incorporate enhanced improvements similar to what is proposed on the State highway system at select problem intersections. Signalized intersections are not included since it assumed that the local agency intersection crash problem is predominantly at rural unsignalized intersections.

The initial identification of potential municipalities and local roads with sections that meet the threshold levels (shown in Table 16) indicates that deploying municipal-wide innovative intersection sign and marking systems is projected to reduce intersection serious injuries and deaths by 9 on an annual basis and cost $2.0 million.

Table 16. Cost and Impact Summary – Local Roads Intersection Safety Initiatives

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