CMF / CRF Details

CMF ID: 8727

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)
Adjusted Standard Error:
Unadjusted Standard Error:0.164
Crash Reduction Factor (CRF)
Value:11.2  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:16.4
Crash Type:Other
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
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
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):59.3 crashes before, 47 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 fatal and injury intersection crashes for drivers at age of 65 or older