CMF / CRF Details

CMF ID: 6858

Install adaptive traffic signal control

Description: ATSC is a traffic management strategy in which traffic signal timings change, or adapt, based on observed traffic demand. These systems utilize increased detection to continually collect data on observed demand, and signal timings are then re-optimized based on current data.

Prior Condition:  Intersections with regular traffic signals

Category: Intersection traffic control

Study: Estimation of the Safety Effects of an Adaptive Traffic Signal Control System, Ma et al., 2015

 
Star Quality Rating:3 Stars  [View score details]
Rating Points Total:95
Crash Modification Factor (CMF)
Value:0.79
Adjusted Standard Error:
Unadjusted Standard Error:0.05
Crash Reduction Factor (CRF)
Value:21  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:5
Applicability
Crash Type:All
Crash Severity:All
Roadway Types:All
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 and suburban
Traffic Volume:
Average Traffic Volume:
Time of Day:All
If countermeasure is intersection-based
Intersection Type:Not specified
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:2006 to 2013
Municipality:
State:VA
Country:
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (sites):38 sites before, 38 sites after
Sample Size (site-years):190 site-years before
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Nov 01, 2015
Comments: 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.