CMF / CRF Details

CMF ID: 7009

Improve pavement friction (Chip Seal)

Description: Chip seal treatment to improve pavement friction

Prior Condition: No Prior Condition(s)

Category: Roadway

Study: Evaluation of Pavement Safety Performance, Merritt et al., 2015

Star Quality Rating: 5 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.883
Adjusted Standard Error:
Unadjusted Standard Error: 0.028
Crash Reduction Factor (CRF)
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Type: Run off road
Crash Severity: All
Roadway Types: Not specified
Number of Lanes: 2
Road Division Type: All
Speed Limit:
Area Type: All
Traffic Volume: Minimum of 170 to Maximum of 24792 Annual Average Daily Traffic (AADT)
Average Traffic Volume: 2751 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: 2000 to 2011
State: CA, MN, NC, PA
Country: USA
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (miles): 2448 miles before, 2448 miles after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Nov-01-2015