CMF / CRF Details

CMF ID: 9890

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:125
Crash Modification Factor (CMF)
Value:0.89
Adjusted Standard Error:
Unadjusted Standard Error:0.079
Crash Reduction Factor (CRF)
Value:11  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:7.9
Applicability
Crash Type:Other
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
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:Minimum of 9912 to Maximum of 36500 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:Minimum of 4133 to Maximum of 26148 Annual Average Daily Traffic (AADT)
Average Major Road Volume :19546 Annual Average Daily Traffic (AADT)
Average Minor Road Volume :12917 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used:2005 to 2014
Municipality:Chicago
State:IL
Country:
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):398 crashes before, 206 crashes after
Sample Size (sites):27 sites before, 27 sites after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 11, 2019
Comments:Crash Type = Vehicle-Vehicle Crashes