CMF / CRF Details

CMF ID: 7949

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:3 Stars  [View score details]
Rating Points Total:105
Crash Modification Factor (CMF)
Value:1.097
Adjusted Standard Error:
Unadjusted Standard Error:0.15
Crash Reduction Factor (CRF)
Value:-9.7  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:15
Applicability
Crash Type:Multiple vehicle
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: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:2006 to 2011
Municipality:Naples
State:notusa
Country:Italy
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):118 crashes before, 81 crashes after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 08, 2016
Comments:CMF applies to spillover effect at nearby untreated sites for multi-vehicle, non-rear-end crashes. The authors note that crash reduction effects decreased over time and speed, speed variability, and non-compliance to speed limits significantly increased over time.