CMF / CRF Details
CMF ID: 4163
Change permissive left-turn phasing to protected only
Description: Treatment group includes intersections where signal phases were changed from permissive to protected-only.
Prior Condition: Treatment group includes intersections where signal phases were changed from permissive to protected-only.
Category: Intersection traffic control
Study: Left-turn Phase: Permissive, Protected, or Both?, Li Chen, Cynthia Chen, and Reid Ewing, 2012
Star Quality Rating: | [View score details] |
Rating Points Total: | 45 |
Crash Modification Factor (CMF) | |
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Value: | 0.36 |
Adjusted Standard Error: | |
Unadjusted Standard Error: |
Crash Reduction Factor (CRF) | |
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Value: | 64 (This value indicates a decrease in crashes) |
Adjusted Standard Error: | |
Unadjusted Standard Error: |
Applicability | |
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Crash Type: | Head on,Sideswipe |
Crash Severity: | All |
Roadway Types: | Not Specified |
Street Type: | |
Minimum Number of Lanes: | 1 |
Maximum Number of Lanes: | 5 |
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: | All |
If countermeasure is intersection-based | |
Intersection Type: | Roadway/roadway (not interchange related) |
Intersection Geometry: | 3-leg,4-leg,More than 4 legs |
Traffic Control: | Signalized |
Major Road Traffic Volume: | |
Minor Road Traffic Volume: | |
Average Major Road Volume : | |
Average Minor Road Volume : |
Development Details | |
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Date Range of Data Used: | 1995 to 2009 |
Municipality: | New York City |
State: | NY |
Country: | USA |
Type of Methodology Used: | Simple before/after |
Sample Size (crashes): | 49 crashes before, 7 crashes after |