CMF / CRF Details

CMF ID: 7796

10-ft to 20-ft conversion (median width)

Description: Conversion of 10-ft traversible median to 20-ft traversible median on rural four-lane road with full access control

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: 2 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.98
Adjusted Standard Error:
Unadjusted Standard Error: 0.01
Crash Reduction Factor (CRF)
Value: 2   (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
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
Municipality:
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): 371 mile-years
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Mar-08-2016
Comments: CMFs of increasing median with from 10ft to 20 ft on urban 5-lane or more roadways with full access control