CMF / CRF Details

CMF ID: 9142

Install automated section speed enforcement system

Description: Installation of automated speed enforcement system. Determines average speed of vehicle over a long distance.

Prior Condition:  Fixed Speed Cameras (FCS) for speed at a specific point, converted to Average Speed Control (ASC)

Category: Advanced technology and ITS

Study: Safety Impact of Average Speed Control in the UK, Lahrmann et al., 2016

Image: View the countermeasure image.

Star Quality Rating:2 Stars  [View score details]
Rating Points Total:40
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.07
Crash Reduction Factor (CRF)
Value:30  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:7
Crash Type:All
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types:Principal Arterial Other Freeways and Expressways
Street Type:
Minimum Number of Lanes:4
Maximum Number of Lanes:4
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:Divided by Median
Minimum Speed Limit:70
Maximum Speed Limit:70
Speed Unit:mph
Speed Limit Comment:
Area Type:All
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:
Municipality:Cambridge and Huntingdon
Country:United Kingdom
Type of Methodology Used:Simple before/after
Sample Size (crashes):246 crashes before, 173 crashes after
Sample Size (sites):6 sites before, 6 sites after
Sample Size (site-years):18 site-years before, 18 site-years after
Sample Size (miles):8.7 miles before, 8.7 miles after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Jan 17, 2018