CMF / CRF Details

CMF ID: 6632

Change horizontal curve radius from straight tangent to radius of R feet (at speed limit of V in mph)

Description:

Prior Condition: No Prior Condition(s)

Category: Alignment

Study: Evaluating the Need for Surface Treatments to Reduce Crash Frequency on Horizontal Curves, Pratt et al., 2014

 
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Crash Modification Factor (CMF)
Value: Equation
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value:
Adjusted Standard Error:
Unadjusted Standard Error:
Applicability
Crash Type: Wet road
Crash Severity: K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types: Principal Arterial Interstate
Number of Lanes: 4
Road Division Type: Divided by Median
Speed Limit: 80
Area Type:
Traffic Volume: Minimum of 972 to Maximum of 70368 Average Daily Traffic (ADT)
Average Traffic Volume: 15633 Average Daily Traffic (ADT)
Time of Day: Not specified
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 2011
Municipality:
State: TX
Country: USA
Type of Methodology Used: Regression cross-section
Sample Size (crashes): 411 crashes
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jun-22-2015
Comments: For situations where the existing (prior) condition is not a straight tangent, calculate CMFs separately for the existing condition and the proposed condition and then divide the proposed condition CMF by the existing condition CMF to arrive at the final CMF.