CMF / CRF Details
CMF ID: 4471
Change permissive left-turn phasing to protected/permissive
Description: Treatment group includes intersections where signal phases were changed from permissive to protected/permissive.
Prior Condition: Permissive only left turn phasing on all treated approaches.
Category: Intersection traffic control
Study: Crash Modification Factors for Changing Left Turn Phasing, Srinivasan et al., 2012
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 130 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 1.075 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.036 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | -7.5 (This value indicates an increase in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 3.6 |
| Applicability | |
|---|---|
| Crash Type: | Rear end |
| Crash Severity: | All |
| Roadway Types: | Not specified |
| 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: | Urban |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | Not specified |
| If countermeasure is intersection-based | |
| Intersection Type: | Roadway/roadway (not interchange related) |
| Intersection Geometry: | 4-leg |
| Traffic Control: | Signalized |
| Major Road Traffic Volume: | Minimum of 4857 to Maximum of 74990 Annual Average Daily Traffic (AADT) |
| Minor Road Traffic Volume: | Minimum of 1466 to Maximum of 42723 Annual Average Daily Traffic (AADT) |
| Average Major Road Volume : | 31537 Annual Average Daily Traffic (AADT) |
| Average Minor Road Volume : | 16292 Annual Average Daily Traffic (AADT) |
| Development Details | |
|---|---|
| Date Range of Data Used: | |
| Municipality: | Toronto and North Carolina |
| State: | notusa,NC |
| Country: | Canada and USA |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 2541 crashes before, 2503 crashes after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Nov 01, 2012 |
| Comments: | |
