CMF / CRF Details
CMF ID: 6867
Widen Narrow Pavement
Description: Widen narrow pavement through wider lanes and/or shoulders
Prior Condition: Total pavement width of 18 to 22 ft
Category: Roadway
Study: Empirical Bayes Before-After Study on Safety Effect of Narrow Pavement Widening Projects in Texas, Wu et al., 2015
Star Quality Rating: | [View score details] |
Rating Points Total: | 135 |
Crash Modification Factor (CMF) | |
---|---|
Value: | 0.683 |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 0.074 |
Crash Reduction Factor (CRF) | |
---|---|
Value: | 31.7 (This value indicates a decrease in crashes) |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 7.4 |
Applicability | |
---|---|
Crash Type: | All |
Crash Severity: | O (property damage only) |
Roadway Types: | Not specified |
Street Type: | |
Minimum Number of Lanes: | 2 |
Maximum Number of Lanes: | 2 |
Number of Lanes Direction: | |
Number of Lanes Comment: | |
Crash Weather: | Not specified |
Road Division Type: | Undivided |
Minimum Speed Limit: | |
Maximum Speed Limit: | |
Speed Unit: | |
Speed Limit Comment: | |
Area Type: | Rural |
Traffic Volume: | Minimum of 487 to Maximum of 7417 Annual Average Daily Traffic (AADT) |
Average Traffic Volume: | 2573 Annual Average Daily Traffic (AADT) |
Time of Day: | All |
If countermeasure is intersection-based | |
Intersection Type: | |
Intersection Geometry: | |
Traffic Control: | |
Major Road Traffic Volume: | |
Minor Road Traffic Volume: | |
Average Major Road Volume : | |
Average Minor Road Volume : |
Development Details | |
---|---|
Date Range of Data Used: | 2003 to 2012 |
Municipality: | |
State: | TX |
Country: | USA |
Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
Sample Size (crashes): | 220 crashes before, 146 crashes after |
Sample Size (sites): | 22 sites before, 22 sites after |
Sample Size (site-years): | 91.67 site-years before, 99 site-years after |
Sample Size (miles): | 77.88 miles before, 77.88 miles after |
Sample Size (miles): | 324.5 mile-years before, 350.5 mile-years after |