CMF / CRF Details

CMF ID: 7723

Install automated section speed enforcement system

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

Prior Condition:  No Point-to-Point Automated Section Speed Enforcement System

Category: Advanced technology and ITS

Study: Effects on Speed and Safety of Point-to-Point Speed Enforcement Systems: Evaluation on the Urban Motorway A56 Tangenziale di Napoli, Montella, et al., 2005

Image: View the countermeasure image.

Star Quality Rating:5 Stars  [View score details]
Rating Points Total:135
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.06
Crash Reduction Factor (CRF)
Value:33.4  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:6
Crash Type:All
Crash Severity:All
Roadway Types:Principal Arterial Other Freeways and Expressways
Street Type:
Minimum Number of Lanes:6
Maximum Number of Lanes:6
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:Divided by Median
Minimum Speed Limit:80
Maximum Speed Limit:80
Speed Unit:km/h
Speed Limit Comment:
Area Type:Urban
Traffic Volume:
Average Traffic Volume:
Time of Day:Day
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:2006 to 2011
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):401 crashes before, 196 crashes after
Sample Size (sites):167 sites before, 167 sites after
Sample Size (site-years):514 site-years before, 486 site-years after
Sample Size (miles):25 miles before, 25 miles after
Sample Size (miles):77 mile-years before, 73 mile-years after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 08, 2016
Comments:The authors note that crash reduction effects decreased over time and speed, speed variability, and non-compliance to speed limits significantly increased over time.