CMF / CRF Details

CMF ID: 2438

Install chevron signs on horizontal curves

Description: Along a curve with a small radius, large deflection angle, available sight distance smaller than stopping sight distance, and superelevation smaller than demanded at design and operating speed.

Prior Condition: No sign

Category: Signs

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

 
Star Quality Rating: 4 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.84
Adjusted Standard Error:
Unadjusted Standard Error: 0.104
Crash Reduction Factor (CRF)
Value: 16 (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 10.4
Applicability
Crash Type: Non-intersection
Crash Severity: Fatal,Serious injury,Minor injury
Roadway Types: All
Number of Lanes: 2
Road Division Type: Undivided
Speed Limit:
Area Type: Rural
Traffic Volume: 261 to 14790 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:
Development Details
Date Range of Data Used: 1993 to 2007
Municipality:
State: WA
Country:
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size Used: Mile-years
Before Sample Size Used: 72 Mile-years
After Sample Size Used: 95 Mile-years
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: 08-11-2010
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.