CMF / CRF Details

CMF ID: 9898

Change permissive left-turn phasing to protected only or protected/permissive

Description: Treatment group includes intersections where signal phases were changed from permissive to protected-only or protected/permissive.

Prior Condition:  Intersections with permissive left-turn signal phasing.

Category: Intersection traffic control

Study: Safety Evaluation of Protected Left-Turn Phasing and Leading Pedestrian Intervals on Pedestrian Safety, Goughnour et al., 2018

 
Star Quality Rating:4 Stars  [View score details]
Rating Points Total:130
Crash Modification Factor (CMF)
Value:1.023
Adjusted Standard Error:
Unadjusted Standard Error:0.016
Crash Reduction Factor (CRF)
Value:-2.3  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:1.6
Applicability
Crash Type:Other
Crash Severity:All
Roadway Types:All
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:
Traffic Volume:
Average Traffic Volume:
Time of Day:All
If countermeasure is intersection-based
Intersection Type:Roadway/roadway (not interchange related)
Intersection Geometry:Not specified
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:2001 to 2014
Municipality:Chicago, New York City, Toronto
State:notusa,IL,NY
Country:USA, Canada
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):13767 crashes before, 10529 crashes after
Sample Size (sites):148 sites before, 148 sites after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 11, 2019
Comments:Crash Type = Vehicle-Vehicle Crashes