01626313

Component

https://doi.org/10.3141/2636-10

Packages of intersection treatments—including signing, pavement marking, and signal enhancements—were installed at many signalized and stop-controlled intersections in South Carolina. This study evaluated the overall safety-effectiveness of the concurrent implementation of these systemic low-cost treatments as part of the FHWA Evaluations of Low Cost Safety Improvements Pooled Fund. The data set included both urban and rural three-leg and four-leg intersections with two or four lanes on the major road. The study employed an empirical Bayes before-and-after analysis. The aggregate results indicate reductions for all crash types analyzed in this study. For signalized intersections, the crash modification factors (CMFs) are 0.955, 0.893, 0.974, 0.883, and 0.969 for total, fatal and injury, rear-end, right-angle, and nighttime crashes, respectively. The CMFs for fatal and injury and right-angle crashes are statistically significant at the 95% confidence level and the CMF for total crashes is statistically significant at the 90% confidence level. For stop-controlled intersections, the CMFs are 0.917, 0.899, 0.933, 0.941, and 0.853 for total, fatal and injury, rear-end, right-angle, and nighttime crashes, respectively. All CMFs for stop-controlled intersections are statistically significant at the 95% confidence level. An economic analysis shows that systemic, low-cost intersection treatments are cost-effective with conservative benefit–cost ratio estimates of 4.1 for total crashes at signalized intersections and 12.4 for total crashes at stop-controlled intersections.

01626186

17-05379

English

pp 80–87

2017

Transportation Research Record: Journal of the Transportation Research Board

9780309441773

Digital/other

References (25) ; Tables (7)

Benefit cost analysis; Crash characteristics; Crash modification factors; Highway safety; Multiway stop signs; Signalized intersections; Traffic control devices

South Carolina

Highways; Operations and Traffic Management; Safety and Human Factors

PRP, TRIS, TRB, ATRI

Dec 8 2016 12:07PM

• Alternative Approach for Combining Multiple Crash Modification Factors Using Adjustment Function and Analytic Hierarchy Process
• Application of Highway Safety Manual Method for Ramp Crash Prediction to Loop and Diamond Ramps
• Developing Crash Modification Factors for Horizontal Curves on Rural Two-Lane Undivided Highways Using a Cross-Sectional Study
• Development of Crash Modification Factors for Uncontrolled Pedestrian Crossing Treatments
• Evaluation of Safety Performance Functions Based on Experimental Design Using a Cross-Validation Method
• Exploring the Need for Region-Specific Calibration Factors
• Implementing Highway Safety Manual Life-Cycle Benefit–Cost Analysis of Safety Improvements
• Investigation of Skew Angle and Other Factors Influencing Crash Frequency at High-Speed Rural Intersections
• Safety Performance of Flashing Yellow Arrow for Protected–Permissive Left-Turn Signal Control in Central Illinois