CMF / CRF Details
CMF ID: 10258
Set posted speed limit 25 mph below engineering recommendations
Description:
Prior Condition: Posted speed limit set equal to engineering recommendations.
Category: Speed management
Study: Safety and Operational Impacts of Setting Speed Limits below Engineering Recommendations, Vikash, V.G., E.T. Donnell, Z. Yu, and L.Li., 2018
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 105 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 4.57 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 14.55 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | -357 (This value indicates an increase in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 1455 |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
| Roadway Types: | All |
| Street Type: | |
| Minimum Number of Lanes: | |
| Maximum Number of Lanes: | |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | Rural |
| Traffic Volume: | |
| 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: | 2000 to 2015 |
| Municipality: | |
| State: | MT |
| Country: | |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 2 crashes after |
| Sample Size (sites): | 1 sites before, 1 sites after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Dec 07, 2019 |
| Comments: | |
