CMF / CRF Details

CMF ID: 7827

Convert 12-foot lanes to 10-foot lanes

Description: Convert 12-foot lanes to 10-foot lanes

Prior Condition: Roadway with 12-foot lanes

Category: Roadway

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: 85
Crash Modification Factor (CMF)
Value: 0.58
Adjusted Standard Error:
Unadjusted Standard Error: 0.13
Crash Reduction Factor (CRF)
Value: 42   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 13
Crash Type: All
Crash Severity: All
Roadway Types: Not specified
Number of Lanes: >2
Road Division Type: Divided by Median
Speed Limit:
Area Type: Rural
Traffic Volume: Minimum of 1600 to Maximum of 139000 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: 7
Sample Size (crashes): 678 crashes
Sample Size (sites): 415 sites
Sample Size (site-years): 1245 site-years
Sample Size (miles): 262.72 miles
Sample Size (mile-years): 788 mile-years
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Mar-08-2016
Comments: CMFs of narrowing lane width from 12 feet to 10 feet on rural divided multi-lane roadways. Speed limit here is the average speed limit.