CMF / CRF Details
Improve Curve Delineation
Countermeasure ID: 10609
Description: Treatments can include new chevrons, horizontal arrows, and advance warning signs as well as the improvement of existing signs using fluorescent yellow sheeting.
Prior Condition: No Prior Condition(s)
Category: Signs
Study: Safety Evaluation of Improved Curve Delineation, Srinivasan et al., 2009
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 120 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.914 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.064 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 8.6 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 6.4 |
| Applicability | |
|---|---|
| Crash Type: | Non-intersection |
| Crash Severity: | All |
| Roadway Types: | All |
| 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 354 to Maximum of 20479 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | |
| 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: | 1993 to 2007 |
| Municipality: | |
| State: | CT,WA |
| Country: | |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 726 crashes before, 516 crashes after |
| Sample Size (sites): | 228 sites before, 228 sites after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Jan 01, 1970 |
| Comments: | |
