CMF / CRF Details

CMF ID: 8419

Install w-beam guardrail

Description: Install w-beam guardrail

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: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 1.01
Adjusted Standard Error:
Unadjusted Standard Error: 0.09
Crash Reduction Factor (CRF)
Value: -1 (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 9
Applicability
Crash Type: Day time,Run off road
Crash Severity: Fatal,Serious injury,Minor injury
Roadway Types: Principal Arterial Other Freeways and Expressways
Number of Lanes: 2 to 5
Road Division Type:
Speed Limit: 50-70 mph
Area Type: Not specified
Traffic Volume: Minimum of 35000 to Maximum of 104600 Annual Average Daily Traffic (AADT)
Time of Day: Day
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry:
Traffic Control:
Major Road Traffic Volume:
Minor Road Traffic 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 (sites): 127 sites before, 127 sites after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jan-17-2017
Comments:

[View the Full Study Details]

The information contained in the Crash Modification Factors (CMF) Clearinghouse is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in the CMF Clearinghouse. The information contained in the CMF Clearinghouse does not constitute a standard, specification, or regulation, nor is it a substitute for sound engineering judgment.