CMF / CRF Details

CMF ID: 7962

Add a through lane on both directions and a raised median

Description:

Prior Condition:  Two-lane undivided roadways

Category: Roadway

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

 
Star Quality Rating:1 Star  [View score details]
Rating Points Total:30
Crash Modification Factor (CMF)
Value:0.28
Adjusted Standard Error:
Unadjusted Standard Error:0.01
Crash Reduction Factor (CRF)
Value:72  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:1
Applicability
Crash Type:All
Crash Severity:All
Roadway Types:Not specified
Street Type:
Minimum Number of Lanes:2
Maximum Number of Lanes:2
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:Undivided
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:
Traffic Control:
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:
Municipality:
State:FL
Country:USA
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (sites):24 sites before, 24 sites after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 08, 2016
Comments:CMF for Adding Lanes applies for median width in the after period of greater than 30 ft 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.

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