CMF / CRF Details

CMF ID: 5633

Change street surface condition from poor to good

Description: Pedestrian crashes only at road segments. Street surface conditions: Poor: serious potholes or other hazards Fair: minor bumps, dips, or rough pavement Good: smooth and free of hazards

Prior Condition:  Roadways with poor pavement condition

Category: Roadway

Study: Estimation of the Safety Effect of Pavement Condition on Rural Two-Lane Highways, Zeng et al., 2014

 
Star Quality Rating:4 Stars  [View score details]
Rating Points Total:120
Crash Modification Factor (CMF)
Value:0.77
Adjusted Standard Error:
Unadjusted Standard Error:0.161
Crash Reduction Factor (CRF)
Value:23  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:16.1
Applicability
Crash Type:All
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types:Not specified
Street Type:
Minimum Number of Lanes:2
Maximum Number of Lanes:2
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:Undivided
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Rural
Traffic Volume:Minimum of 410 to Maximum of 26943 Annual Average Daily Traffic (AADT)
Average Traffic Volume:4209 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 2011
Municipality:
State:VA
Country:USA
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (sites):69 sites before, 69 sites after
Sample Size (site-years):138 site-years before, 138 site-years after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Aug 12, 2014
Comments:CMF of changing pavement condtion from poor(CCI below 60) to good (CCI beyond 70)at road segments with 10ft lanes and 3ft or 4ft shoulders The number of crashes in the after period were not reported in this study, however, they have been recorded as 300 to give 10 points as a beneift of doubt for one or more of the following: (1) number of miles/sites in the reference/treatment group, (2) number of crashes in the references/treatment group, (3) reporting AADTs for the aggregate dataset but not for the disaggragate dataset used for CMF development.