CMF / CRF Details
CMF ID: 9401
Change from protected only to flashing yellow arrow protected/permissive left turn
Description: Change from protected only to FYA - protected/permissive left turn
Prior Condition: Protected left-turn phasing on the approach.
Category: Intersection traffic control
Study: Approach-Level Safety Comparison of Permissive-Protected and Protected Left Turn Phasing to Flashing Yellow Areas, Shea and Medina, 2018
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 90 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 3.428 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.3093 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | -242.8 (This value indicates an increase in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 30.93 |
| Applicability | |
|---|---|
| Crash Type: | Left turn |
| 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: | Not specified |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | All |
| If countermeasure is intersection-based | |
| Intersection Type: | Not specified |
| Intersection Geometry: | |
| 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: | 2011 to 2016 |
| Municipality: | |
| State: | UT |
| Country: | United States |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 64 crashes before, 180 crashes after |
| Sample Size (sites): | 40 sites before, 40 sites after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Oct 27, 2018 |
| Comments: | This CMF applies at the approach level, not at the intersection level. |
