CMF / CRF Details

CMF ID: 4366

Installing red light running (RLR) cameras for four-way signalized intersection

Description: Installing red light running cameras only on the approaches with high potential for crashes

Prior Condition:  No red light running cameras on any of the signalized intersection approaches

Category: Advanced technology and ITS

Study: Red Light Running Camera Assessment, Sperley Ross, 2011

Star Quality Rating:1 Star  [View score details]
Rating Points Total:10
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.24
Crash Reduction Factor (CRF)
Value:-23  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:24
Crash Type:Angle,Rear end,Sideswipe
Crash Severity:B (minor injury),O (property damage only)
Roadway Types:Major Collector
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:Undivided
Minimum Speed Limit:40
Maximum Speed Limit:40
Speed Unit:mph
Speed Limit Comment:
Area Type:Urban
Traffic Volume:
Average Traffic Volume:
Time of Day:Not specified
If countermeasure is intersection-based
Intersection Type:Roadway/roadway (not interchange related)
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:2004 to 2009
Type of Methodology Used:Simple before/after
Sample Size (crashes):77 crashes before, 40 crashes after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Dec 06, 2012
Comments:- The report compares the monthly average of crashes.- The before period is 50 months and the after period is 21 months.- This CMF considers crashes on the approaches that have RLR cameras installed.- This CMF covers ONLY a part of the area of influence of these approaches, in order to compare it to the adjacent 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.