CMF / CRF Details
CMF ID: 10479
Increase speed limit from 55 mph to 60 mph
Description:
Prior Condition: Posted speed limit of 55 mph
Category: Speed management
Study: Speed Limit Change (55 mph to 60 mph) Safety Evaluation, Saleem et al., 2020
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 110 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 1.348 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.339 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | -34.8 (This value indicates an increase in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 33.9 |
| Applicability | |
|---|---|
| Crash Type: | Rear end |
| 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: | 60 |
| Maximum Speed Limit: | 60 |
| Speed Unit: | mph |
| Speed Limit Comment: | |
| Area Type: | Rural |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | All |
| If countermeasure is intersection-based | |
| Intersection Type: | Roadway/roadway (not interchange related) |
| Intersection Geometry: | 4-leg |
| Traffic Control: | Other |
| Major Road Traffic Volume: | |
| Minor Road Traffic Volume: | |
| Average Major Road Volume : | |
| Average Minor Road Volume : | |
| Development Details | |
|---|---|
| Date Range of Data Used: | 2012 to 2018 |
| Municipality: | |
| State: | MN |
| Country: | |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 21 crashes after |
| Sample Size (sites): | 92 sites before, 92 sites after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Aug 14, 2020 |
| Comments: | This CMF is for 4-Leg Intersections (all Control Types) with Lighting. |
