CMF / CRF Details

CMF ID: 4167

Changing left turn phasing on one approach from permissive to protected-permissive

Description: CMFs are calculated the intersection level and not the treated approach(es) level.

Prior Condition:  Permissive only left turn phasing on the treated approach

Category: Intersection traffic control

Study: Evaluation of Safety Strategies at Signalized Intersections, Srinivasan, et al., 2011

Star Quality Rating:5 Stars  [View score details]
Rating Points Total:140
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.045
Crash Reduction Factor (CRF)
Value:-9.4  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:4.5
Crash Type:Rear end
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:Urban
Traffic Volume:
Average Traffic Volume:
Time of Day:Not specified
If countermeasure is intersection-based
Intersection Type:Roadway/roadway (not interchange related)
Intersection Geometry:4-leg
Traffic Control:Signalized
Major Road Traffic Volume:Minimum of 4857 to Maximum of 74990 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:Minimum of 1466 to Maximum of 42723 Annual Average Daily Traffic (AADT)
Average Major Road Volume :31537 Annual Average Daily Traffic (AADT)
Average Minor Road Volume :16292 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used:
Municipality:Toronto & North Carolina
Country:Canada & USA
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):1935 crashes before, 1434 crashes after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Dec 06, 2012