CMF / CRF Details

CMF ID: 7852

Install left-turn lane

Description:

Prior Condition: Intersections without left-turn lanes

Category: Intersection geometry

Study: Validation and Application of Highway Safety Manual (Part D) in Florida, Abdel-Aty et al., 2014

 
Star Quality Rating: 3 Stars   [View score details]
Rating Points Total: 95
Crash Modification Factor (CMF)
Value: 0.73
Adjusted Standard Error:
Unadjusted Standard Error: 0.17
Crash Reduction Factor (CRF)
Value: 27   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 17
Applicability
Crash Type: All
Crash Severity: K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types: Not specified
Number of Lanes:
Road Division Type:
Speed Limit:
Area Type: Rural
Traffic Volume:
Average Traffic Volume:
Time of Day: All
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry: 3-leg
Traffic Control: Stop-controlled
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used: 2007 to 2011
Municipality:
State: FL
Country: USA
Type of Methodology Used: 2
Sample Size (sites): 18 sites before, 18 sites after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Mar-08-2016
Comments: The number of crashes in the after period were not reported in this study, however, they have been recorded as 300 to give 10 points as a beneift of doubt for one or more of the following: (1) number of miles/sites in the reference/treatment group, (2) number of crashes in the references/treatment group, (3) reporting AADTs for the aggregate dataset but not for the disaggragate dataset used for CMF development.