Delta Region Transportation Development Program: Rural Safety Innovation Program Evaluation – Final Report

February 2014

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

Metric Conversion Chart

SI (Modern Metric) Conversion Factors

Contents

Executive Summary

Chapter 1. Introduction

• Background
• Objective and Scope
• Research Approach
• Outline of Report

Chapter 2. Detailed Quantitative

• Evaluations
• RSIP Project 27
• RSIP Project 36
• RSIP Project 37
• Summary

Chapter 3. Simpler Quantitative Evaluation

• RSIP Project 33

Chapter 4. Qualitative Evaluations

• RSIP Project 25
• RSIP Project 32

Chapter 5. Conclusions

Chapter 6. References

List of Tables

Table 1. Agencies and Countermeasures Involved in the RSIP-DRTDP

Table 2. Levels of Evaluation and Agencies Involved

Table 3. RSIP Project 27: Approximate Locations of Centerline Rumble Strip Installations from the RSIP in Mississippi

Table 4. RSIP Project 27: Location of Treatment Sites Used in Analysis of Dual Application of Centerline and Shoulder Rumble Strips in Mississippi

Table 5. RSIP Project 27: Location of Nontreatment Sites Used in Analysis of Dual Application of Centerline and Shoulder Rumble Strips in Mississippi

Table 6. RSIP Project 27: Summary Statistics for the Before and After Periods for Treatment Sites in Mississippi

Table 7. RSIP Project 27: Summary Statistics for Entire Study Period for Nontreatment Sites in Mississippi

Table 8. RSIP Project 27: SPF Coefficients, Target Crash Proportions, and CalibrationFactors Used for Mississippi Data

Table 9. RSIP Project 27: Safety Effectiveness of Dual Application of Centerline and Shoulder Rumble Strips on Target Crashes in Mississippi

Table 10. RSIP Project 36: RSIP Safety Improvements in Illinois by County

Table 11. RSIP Project 36: Location of Treatment Sites in Illinois and Types of Safety Improvements

Table 12. RSIP Project 36: Location of Nontreatment Sites in Illinois

Table 13. RSIP Project 36: Summary Statistics for the Before and After Periods for Treatment Sites in Illinois

Table 14. RSIP Project 36: Summary Statistics for the Entire Study Period for Nontreatment Sites in Illinois

Table 15. RSIP Project 36: Target Crash Proportions and Calibration Factors Used for Illinois Data

Table 16. RSIP Project 36: Safety Effectiveness of Horizontal Curve Delineation and Signing on Total Crashes in Illinois

Table 17. RSIP Project 36: Safety Effectiveness of Horizontal Curve Delineation and Signing on SVROR Crashes in Illinois

Table 18. RSIP Project 37: Location of Treatment Sites in Louisiana and Types of Safety Improvements

Table 19. RSIP Project 37: Summary Statistics for the Before and After Treatment Periods for Treatment Intersections in Louisiana–All Collision Types

Table 20. RSIP Project 37: Summary Statistics for the Entire Study Period for Nontreatment Intersections in Louisiana-All Collision Types

Table 21. RSIP Project 37: Summary Statistics for the Before and After Treatment Periods for Treatment Intersections in Louisiana–Target Crashes

Table 22. RSIP Project 37: Summary Statistics for the Entire Study Period for Nontreatment Intersections in Louisiana–Target Crashes

Table 23. RSIP Project 37: Breakdown of Louisiana Intersections by Facility Type and Number of Legs

Table 24. RSIP Project 37: SPF Coefficients, Target Crash Proportions,and Calibration Factors Used for Louisiana Intersection Data

Table 25. RSIP Project 37: Combined Intersection CMFs Used for Louisiana Treatment Intersections

Table 26. RSIP Project 37: Combined Intersection CMFs Used for Louisiana Nontreatment Intersections

Table 27. RSIP Project 37: Safety Effectiveness of Combination Intersection Improvements on Total and Target Crashes in Louisiana–Three-Leg Stop– Controlled Intersections on Rural Two-Lane Roads

Table 28. RSIP Project 37: Safety Effectiveness of Combination Intersection
Improvements on Total and Target Crashes in Louisiana–Four-Leg Stop-Controlled Intersections on Rural Two-Lane Roads

Table 29. RSIP Project 37: Safety Effectiveness of Combination Intersection Improvements on Total and Target Crashes in Louisiana-Three-Leg Stop- Controlled Intersections on Multilane Highways

Table 30. RSIP Project 33: Summary Statistics for the Before Period for Treatment Sites in Arkansas

Table 31. RSIP Project 33: Summary Statistics for the After Period for Treatment Sites in Arkansas

Table 32. RSIP Project 33: Regression Results and Treatment Effects by Crash Severity

List of Figures

Figure 1. Equation 1 – General form of Safety Analyst SPF for rural two-lane roads for total and fatal and all injury severity levels.

Figure 2. Equation 2 – General form of Safety Analyst SPF for rural two-lane roads adjusted for crash type and local conditions

Figure 3. Equation 3 – General form of HSM SPF for rural two-lane roads for all severity levels combined (total).

Figure 4. Equation 4 – Overdispersion parameter.

Figure 5. Equation 5 – General form of HSM SPF for rural two-lane roads adjusted for crash type, horizontal curvature, and local conditions.

Figure 6. Equation 6 – CMF for horizontal curves on rural two-lane highways

Figure 7. Equation 7 – Equation 6. General form of HSM SPF for intersections on rural two-lane and rural multilane roads for total and fatal and all injury severity levels.

Figure 8. Equation 8 – General form of HSM SPF for intersections on rural two-lane and rural multilane roads adjusted for crash type, combined CMFs, and local conditions

Figure 9. Equation 9 – General model to calculate predicted crashes

Figure 10. RSIP Project 32: Excerpt of Message Log from One DMS

List of Acronyms