CMF / CRF Details

Provide a left-turn lane on one major-road approach

Countermeasure ID: 2968

Description:

Prior Condition: neither approach of the major road of a 3-leg unsignalized intersection has a left-turn lane

Category: Intersection geometry

Study: Using a Reliability Process to Reduce Uncertainty in Predicting Crashes at Unsignalized Intersections, Haleem et al., 2010

 
Star Quality Rating:3 Stars  [View score details]
Rating Points Total:80
Crash Modification Factor (CMF)
Value:0.61
Adjusted Standard Error:
Unadjusted Standard Error:0.07
Crash Reduction Factor (CRF)
Value:39  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:7.3
Applicability
Crash Type:All
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:Not specified
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
Traffic Control:Stop-controlled
Major Road Traffic Volume:Minimum of 7332 to Maximum of 66171 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:2003 to 2006
Municipality:Orange County
State:FL
Country:U.S.A.
Type of Methodology Used:Regression cross-section
Sample Size (crashes):497 crashes
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 21, 2011
Comments:Countermeasure name has been slightly modified for consistency across Clearinghouse

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