CMF / CRF Details

CMF ID: 7731

Install left turn flashing yellow arrow signals and supplemental traffic signs

Description: Install left turn flashing yellow arrow signals with supplemental traffic signs with text "Left Turn Yield on Flashing Yellow Arrow"

Prior Condition:  Permissive phase of the PPLT control operated with a circular green indication

Category: Intersection traffic control

Study: Safety Effects of Traffic Signing for Left Turn Flashing Yellow Arrow Signals, Schattler et al., 2015

 
Star Quality Rating:4 Stars  [View score details]
Rating Points Total:120
Crash Modification Factor (CMF)
Value:0.901
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value:9.87  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Applicability
Crash Type:Other
Crash Severity:All
Roadway Types:All
Street Type:
Minimum Number of Lanes:2
Maximum Number of Lanes:7
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:All
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:
Intersection Geometry:3-leg,4-leg
Traffic Control:Signalized
Major Road Traffic Volume:Minimum of 3250 to Maximum of 37500 Average Daily Traffic (ADT)
Minor Road Traffic Volume:Minimum of 63 to Maximum of 14700 Average Daily Traffic (ADT)
Average Major Road Volume :17215 Average Daily Traffic (ADT)
Average Minor Road Volume :4576 Average Daily Traffic (ADT)
Development Details
Date Range of Data Used:2007 to 2013
Municipality:Peoria
State:IL
Country:USA
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):149 crashes before, 36.02 crashes after
Sample Size (sites):90 sites before, 90 sites after
Sample Size (site-years):270 site-years before
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 08, 2016
Comments:CMFs of left-turn opposing through (LTOT) crashes on signalized intersections, including not interchange related and interchange related intersections. Left-turn opposing through (LTOT) crashes involve one vehicle turning left from one approach and one vehicle going straight from the opposite approach. Applies to approaches with dedicated left turn lanes and PPLT phasing before and after.