CMF / CRF Details

CMF ID: 6616

Change pavement friction from 40 to SK (in friction number)

Description:

Prior Condition: No Prior Condition(s)

Category: Roadway

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: Run off road,Wet road
Crash Severity: K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types: All
Number of Lanes: 2
Road Division Type: Undivided
Speed Limit: 60
Area Type: Not specified
Traffic Volume: Minimum of 14 to Maximum of 40200 Average Daily Traffic (ADT)
Average Traffic Volume: 1443 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): 430 crashes
Sample Size (sites): 386 sites
Sample Size (miles): 4051 miles
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jun-22-2015
Comments: This CMF is for crashes on horizontal curves. For situations where the existing (prior) condition is not friction number of 40, 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.