CMF / CRF Details
CMF ID: 5602
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: Signals with permissive only left turn phasing
Category: Intersection traffic control
Study: Evaluating the Safety Effects of Signal Improvements, Schultz et al., 2014
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 30 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.97 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 3 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | All |
| Roadway Types: | Minor Arterial |
| 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: | 30 |
| Maximum Speed Limit: | 65 |
| Speed Unit: | mph |
| Speed Limit Comment: | |
| Area Type: | Not specified |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | All |
| If countermeasure is intersection-based | |
| Intersection Type: | Not specified |
| Intersection Geometry: | No values chosen. |
| Traffic Control: | Signalized |
| Major Road Traffic Volume: | |
| Minor Road Traffic Volume: | |
| Average Major Road Volume : | |
| Average Minor Road Volume : | |
| Development Details | |
|---|---|
| Date Range of Data Used: | 2002 to 2011 |
| Municipality: | |
| State: | UT |
| Country: | |
| Type of Methodology Used: | Other before/after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Aug 12, 2014 |
| Comments: | The hierachical Bayesian model was used. CMF for roadway types: minor arterial and major collectors. |
