CMF / CRF Details

CMF ID: 1883

Install a combination of chevron signs, curve warning signs, and/or sequential flashing beacons

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 curve delineation treatment. Deflection angle is less than 60 gon.

Category: Signs

Study: Safety Evaluation of Curve Delineation Improvements An Empirical Bayes Observational Before-After Study, Montella, 2009

 
Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.764
Adjusted Standard Error:
Unadjusted Standard Error: 0.13
Crash Reduction Factor (CRF)
Value: 23.6   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 13
Applicability
Crash Type: Run off road
Crash Severity: All
Roadway Types: Principal Arterial Other Freeways and Expressways
Number of Lanes: 4
Road Division Type:
Speed Limit:
Area Type: Not specified
Traffic Volume: Minimum of 7400 to Maximum of 13975 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: 2001 to 2005
Municipality: Trans European Road Network, Italy
State:
Country:
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (sites): 9 sites after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Dec-01-2009
Comments: