CMF / CRF Details

CMF ID: 10276

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:  Time-based coordinated signal system

Category: Intersection traffic control

Study: Safety Analysis and Crash Modification Factors of an Adaptive Signal Control Technology along a Corridor, Osorio, J. and R. Benekohal., 2019

Star Quality Rating:3 Stars  [View score details]
Rating Points Total:95
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.41
Crash Reduction Factor (CRF)
Value:13  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:41
Crash Type:All
Crash Severity:B (minor 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:Roadway/roadway (not interchange related)
Intersection Geometry:3-leg,4-leg
Traffic Control:Signalized
Major Road Traffic Volume:Minimum of 19200 to Maximum of 21370 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:Minimum of 1300 to Maximum of 15560 Annual Average Daily Traffic (AADT)
Average Major Road Volume :20063 Annual Average Daily Traffic (AADT)
Average Minor Road Volume :6928 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used:2012 to 2016
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (sites):6 sites before, 6 sites after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Dec 07, 2019
Comments:This CMF is for Four- and Three-Leg intersections combined and uses calibrated-Illinois SPFs. 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.