CMF / CRF Details
CMF ID: 1871
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. Radius is less than 300 m.
Category: Signs
Study: Safety Evaluation of Curve Delineation Improvements An Empirical Bayes Observational Before-After Study, Montella, 2009
Star Quality Rating: | [View score details] |
Rating Points Total: | 120 |
Crash Modification Factor (CMF) | |
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Value: | 0.635 |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 0.11 |
Crash Reduction Factor (CRF) | |
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Value: | 36.5 (This value indicates a decrease in crashes) |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 11 |
Applicability | |
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Crash Type: | Angle |
Crash Severity: | All |
Roadway Types: | Principal Arterial Other Freeways and Expressways |
Street Type: | |
Minimum Number of Lanes: | 4 |
Maximum Number of Lanes: | 4 |
Number of Lanes Direction: | |
Number of Lanes Comment: | |
Crash Weather: | Not specified |
Road Division Type: | |
Minimum Speed Limit: | |
Maximum Speed Limit: | |
Speed Unit: | |
Speed Limit Comment: | |
Area Type: | Not specified |
Traffic Volume: | Minimum of 7400 to Maximum of 13975 Annual Average Daily Traffic (AADT) |
Average Traffic Volume: | |
Time of Day: | Day |
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 | |
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Date Range of Data Used: | 2001 to 2005 |
Municipality: | Trans European Road Network, Italy |
State: | notusa |
Country: | |
Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
Sample Size (sites): | 10 sites after |
Other Details | |
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Included in Highway Safety Manual? | No |
Date Added to Clearinghouse: | Dec 01, 2009 |
Comments: |