CMF / CRF Details

CMF ID: 8728

Install Box Span Signal


Prior Condition: Intersections with diagonal span signal configurations

Category: Advanced technology and ITS

Study: Safety Evaluation of Box Span Signal Configuration, Yassin et al., 2017

Star Quality Rating: 3 Stars   [View score details]
Rating Points Total: 105
Crash Modification Factor (CMF)
Value: 0.841
Adjusted Standard Error:
Unadjusted Standard Error: 0.133
Crash Reduction Factor (CRF)
Value: 15.9   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 13.3
Crash Type: Angle
Crash Severity: All
Roadway Types: Not specified
Street Type:
Minimum Number of Lanes:
Maximum Number of Lanes: 4
Number of Lanes Direction:
Number of Lanes Comment: < = 4 Lanes
Crash Weather: Not specified
Road Division Type: All
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:
Traffic Volume:
Average Traffic Volume:
Time of Day: All
If countermeasure is intersection-based
Intersection Type: Not specified
Intersection Geometry: 3-leg,4-leg
Traffic Control: Signalized
Major Road Traffic Volume: Minimum of 3220 to Maximum of 66316 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume: Minimum of 471 to Maximum of 53080 Annual Average Daily Traffic (AADT)
Average Major Road Volume : 18476 Annual Average Daily Traffic (AADT)
Average Minor Road Volume : 7094 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used: 2006 to 2011
State: MI
Country: USA
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (crashes): 86.2 crashes before, 61.3 crashes after
Sample Size (sites): 117 sites before, 117 sites after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Nov-17-2017
Comments: CMF of angle crashes for drivers at age of 65 or older