CMF / CRF Details

CMF ID: 7772

Convert a TWLTL to a raised median

Description:

Prior Condition:  Roadway with a TWLTL

Category: Roadway

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

 
Star Quality Rating:2 Stars  [View score details]
Rating Points Total:50
Crash Modification Factor (CMF)
Value:0.67
Adjusted Standard Error:
Unadjusted Standard Error:0.04
Crash Reduction Factor (CRF)
Value:33  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:4
Applicability
Crash Type:All
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
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:Divided by TWLTL
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:
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:2004 to 2012
Municipality:
State:FL
Country:USA
Type of Methodology Used:Before/after using comparison group
Sample Size (crashes):1127 crashes before, 687 crashes after
Sample Size (sites):33 sites before, 33 sites after
Sample Size (miles):9.27 miles before, 9.27 miles 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.