CMF / CRF Details

CMF ID: 2968

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

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]
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
Number of Lanes:
Road Division Type:
Speed Limit:
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