CMF / CRF Details
CMF ID: 4078
Upgrade unpaved or non-existent shoulders to composite shoulders
Description: Upgrade shoulders on rural two-lane roads from unpaved or non-existent shoulders to composite shoulders.
Prior Condition: Unpaved shoulders less than or equal to 5 feet on rural two-lane roads.
Category: Shoulder treatments
Study: Estimation of Safety Effectiveness of Composite Shoulders on Rural Two-Lane Highways, Zeng, H. and S.D. Schrock, 2012
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 90 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.861 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.145 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 13.9 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 14.5 |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | All |
| 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 380 to Maximum of 2340 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | 980 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: | 2000 to 2009 |
| Municipality: | |
| State: | KS |
| Country: | USA |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 112 crashes before, 142 crashes after |
