CMF / CRF Details

CMF ID: 1897

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 curve delineation treatment

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]
Rating Points Total: 95
Crash Modification Factor (CMF)
Value: 1.92
Adjusted Standard Error:
Unadjusted Standard Error: 0.77
Crash Reduction Factor (CRF)
Value: -92   (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 77
Applicability
Crash Type: Nighttime
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 9746
Average Traffic Volume:
Time of Day: Night
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: 2
Sample Size (sites): 4 sites after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Dec-01-2009
Comments: