CMF / CRF Details

CMF ID: 7799

10-ft to 30-ft conversion (median width)

Description: Convert a 10-ft traversable median to a 30-ft traversable median

Prior Condition:  Roadway with a 10ft median

Category: Access management

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:80
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.01
Crash Reduction Factor (CRF)
Value:6  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:1
Crash Type:All
Crash Severity:All
Roadway Types:Not specified
Street Type:
Minimum Number of Lanes:5
Maximum Number of Lanes:
Number of Lanes Direction:
Number of Lanes Comment:> = 5 Lanes
Crash Weather:Not specified
Road Division Type:Divided by Median
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Urban
Traffic Volume:Minimum of 18900 to Maximum of 158000 Annual Average Daily Traffic (AADT)
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:2010 to 2012
Type of Methodology Used:Regression cross-section
Sample Size (sites):143 sites
Sample Size (site-years):429 site-years
Sample Size (miles):124 miles
Sample Size (mile-years):372 mile-years
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 08, 2016
Comments:CMFs of increasing median width from 10 ft to 30 ft on urban 5-lane or more lanes roadways with full access control