CMF / CRF Details

CMF ID: 8347

Install w-beam guardrail or concrete barrier

Description:

Prior Condition:  No roadside barrier

Category: Roadside

Study: Evaluation of the Safety Effectiveness of Installing Roadside Barriers with Different Driver, Vehicle, Weather, and Time of Day Conditions, Park et. al., 2016

 
Star Quality Rating:4 Stars  [View score details]
Rating Points Total:110
Crash Modification Factor (CMF)
Value:0.93
Adjusted Standard Error:
Unadjusted Standard Error:0.05
Crash Reduction Factor (CRF)
Value:7  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:5
Applicability
Crash Type:Run off road
Crash Severity:All
Roadway Types:Principal Arterial Other Freeways and Expressways
Street Type:
Minimum Number of Lanes:2
Maximum Number of Lanes:5
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:
Minimum Speed Limit:50
Maximum Speed Limit:70
Speed Unit:mph
Speed Limit Comment:
Area Type:Not specified
Traffic Volume:Minimum of 35000 to Maximum of 104600 Annual Average Daily Traffic (AADT)
Average Traffic Volume:
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:2003 to 2011
Municipality:
State:FL
Country:
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):789 crashes before, 668 crashes after
Sample Size (sites):147 sites before, 147 sites after
Sample Size (miles):68 miles before, 68 miles after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Jan 17, 2017
Comments:CMF is based on a Full Bayes analysis.