CMF / CRF Details

CMF ID: 3173

Installation of cable barriers in freeway medians

Description: Installation of cable barriers in medians of Interstate locations

Prior Condition: No median barrier

Category: Roadside

Study: Hierarchical Bayesian Modeling for Before and After Studies, Olsen et al., 2011

 
Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.56
Adjusted Standard Error:
Unadjusted Standard Error: 0.104
Crash Reduction Factor (CRF)
Value: 44   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 10.4
Applicability
Crash Type: All
Crash Severity: K (fatal),A (serious injury)
Roadway Types: Principal Arterial Interstate
Number of Lanes:
Road Division Type: Divided by Median
Speed Limit:
Area Type: All
Traffic Volume:
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: 2002 to 2008
Municipality:
State: UT
Country:
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (site-years): 27 site-years before, 15 site-years after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jul-15-2011
Comments: