CMF / CRF Details

CMF ID: 7811

10-ft to 70-ft conversion (median width)

Description: Convert a 10-ft traversable median to a 70-ft traversable median

Prior Condition: Roadways 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: 2 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.91
Adjusted Standard Error:
Unadjusted Standard Error: 0.03
Crash Reduction Factor (CRF)
Value: 9   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 3
Crash Type: All
Crash Severity: All
Roadway Types: Not specified
Number of Lanes: >4
Road Division Type: Divided by Median
Speed Limit:
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
State: FL
Country: USA
Type of Methodology Used: Regression cross-section
Sample Size (sites): 143 sites
Sample Size (site-years): 429 site-years
Sample Size (miles): 123.65 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 widening the median width from 10ft to 70ft on urban 5-lane or more roadways with full access control