CMF / CRF Details

CMF ID: 9414

Convert signal from span wire to mast arm

Description: Convert signals mounted on span wire to signals mounted on mast arm

Prior Condition:  Signalized intersection with signal mounted on a span wire.

Category: Intersection traffic control

Study: Evaluating the Safety Effects of Span Wire to Mast Arm Signal Conversion, Khattak and Fontaine, 2018

 
Star Quality Rating:3 Stars  [View score details]
Rating Points Total:75
Crash Modification Factor (CMF)
Value:1
Adjusted Standard Error:
Unadjusted Standard Error:0.08
Crash Reduction Factor (CRF)
Value:0  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:8
Applicability
Crash Type:All
Crash Severity:All
Roadway Types:Not specified
Street Type:
Minimum Number of Lanes:
Maximum Number of Lanes:
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:Urban and suburban
Traffic Volume:
Average Traffic Volume:
Time of Day:All
If countermeasure is intersection-based
Intersection Type:Not specified
Intersection Geometry:4-leg
Traffic Control:Signalized
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:
Municipality:
State:VA
Country:United States
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (sites):22 sites before, 22 sites after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Oct 27, 2018
Comments:This CMF applies to all crashes at 4-leg urban and suburban signalized intersections. The number of crashes in the after period were not reported in this study, however, they have been recorded as 300 to give 10 points as a beneift of doubt for one or more of the following: (1) number of miles/sites in the reference/treatment group, (2) number of crashes in the references/treatment group, (3) reporting AADTs for the aggregate dataset but not for the disaggragate dataset used for CMF development.