CMF / CRF Details

CMF ID: 5518

Decrease median width from 64ft to 40ft

Description: Decrease median width from 64ft to 40ft

Prior Condition: 64 ft wide median

Category: Access management

Study: Using multivariate adaptive regression splines (MARS) to develop crash modification factors for urban freeway interchange influence areas, Haleem et al., 2013

 
Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 1.43
Adjusted Standard Error:
Unadjusted Standard Error: 0.222
Crash Reduction Factor (CRF)
Value: -43   (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 22.2
Applicability
Crash Type: Rear end
Crash Severity: All
Roadway Types: Principal Arterial Other Freeways and Expressways
Number of Lanes: 4 to 6+
Road Division Type: Divided by Median
Speed Limit:
Area Type: Urban
Traffic Volume: Minimum of 5700 to Maximum of 309000 Annual Average Daily Traffic (AADT)
Average Traffic Volume: 95338 Annual Average Daily Traffic (AADT)
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: 2007 to 2010
Municipality:
State: FL
Country: USA
Type of Methodology Used: Regression cross-section
Sample Size (crashes): 15520 crashes
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Apr-30-2014
Comments: CMF for urban freeway interchange areas