CMF / CRF Details

CMF ID: 7268

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 chevron signs

Category: Signs

Study: Development of Crash Modification Factors of Alignment Elements and Safety Countermeasures for Korean Freeways, Choi et al., 2015

 
Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.721
Adjusted Standard Error:
Unadjusted Standard Error: 0.308
Crash Reduction Factor (CRF)
Value: 27.9   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 30.8
Applicability
Crash Type: All
Crash Severity: All
Roadway Types: Principal Arterial Other Freeways and Expressways
Number of Lanes:
Road Division Type:
Speed Limit:
Area Type:
Traffic Volume: Minimum of 8000 to Maximum of 45000 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 2008
Municipality:
State:
Country: Korea
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (crashes): 44 crashes before, 31 crashes after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Nov-01-2015
Comments: AADT range is for freeways in the reference group.