CMF / CRF Details

CMF ID: 2921

Implement automated speed enforcement cameras


Prior Condition:  No automated speed enforcement demonstration program

Category: Advanced technology and ITS

Study: Evaluation of the Scottsdale Loop 101 automated speed enforcement demonstration program, Shin et al., 2009

Star Quality Rating:4 Stars  [View score details]
Rating Points Total:115
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.14
Crash Reduction Factor (CRF)
Value:48  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:14
Crash Type:All
Crash Severity:A (serious injury),B (minor injury),C (possible injury)
Roadway Types:Principal Arterial Other
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
Traffic Volume:
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 2006
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 21, 2011
Comments:CMF is for "target" crashes. "Target" crashes are defined as those that occur during non-peak periods (specific to TOD). Peak periods (6AM - 9 AM and 4PM - 7PM); Non-peak periods (remaining 18 hrs for weekdays, 24 hrs for weekends and holidays). The authors of this study also experimented with producing additional CMFs from the same dataset using alternative, less reliable methods. Since this did not add new knowledge to this topic, these CMFs were not included in the Clearinghouse.----------The star rating for this CMF was modified from 3 to 4 stars in January 2015. The previous star rating was assigned using a sample size score based only on the crashes in the period after the countermeasure installation. The standard scoring method in the Clearinghouse is to score the sample size based on the crashes before the countermeasure installation plus the expected crashes in the after period.