CMF / CRF Details

CMF ID: 10613

Improve Curve Delineation

Description: Treatments can include new chevrons, horizontal arrows, and advance warning signs as well as the improvement of existing signs using fluorescent yellow sheeting.

Prior Condition:  No Prior Condition(s)

Category: Signs

Study: Safety Evaluation of Improved Curve Delineation, Srinivasan et al., 2009

 
Star Quality Rating:5 Stars  [View score details]
Rating Points Total:140
Crash Modification Factor (CMF)
Value:0.725
Adjusted Standard Error:
Unadjusted Standard Error:0.073
Crash Reduction Factor (CRF)
Value:27.5  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:7.3
Applicability
Crash Type:Non-intersection
Crash Severity:All
Roadway Types:All
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 354 to Maximum of 20479 Annual Average Daily Traffic (AADT)
Average Traffic Volume:
Time of Day:Night
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:1993 to 2007
Municipality:
State:CT,WA
Country:
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):302 crashes before, 176 crashes after
Sample Size (sites):228 sites before, 228 sites after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Jan 01, 1970
Comments: