CMF / CRF Details
Change from protected/permitted to protected only left turn signal control during special time-of-day (left turn crashes)
Countermeasure ID: 2108
Description: Special time-of-day protected/permitted left turn signal control
Prior Condition: urban signalized intersection on 1, 2, and 3-lane roads with exclusive left turn lane
Category: Intersection traffic control
Study: Safety of Special Time-of-Day Protected/Permitted Left-Turn Signal Control Display, Ozmen et al., 2009
| Crash Modification Factor (CMF) |
|---|
| Value: | 0.58 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.37 |
| Crash Reduction Factor (CRF) |
|---|
| Value: | 41.5 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 37 |
| Applicability |
|---|
| Crash Type: | All |
| 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: | 25 |
| Maximum Speed Limit: | 45 |
| Speed Unit: | mph |
| Speed Limit Comment: | |
| Area Type: | Urban |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | All |
| If countermeasure is intersection-based |
| Intersection Type: | Roadway/roadway (not interchange related) |
| 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: | |
| Municipality: | |
| State: | NV |
| Country: | |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Dec 01, 2009 |
| Comments: | Only for left-turn related crashes. |
