CMF / CRF Details

CMF ID: 10634

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: Crash Modification Factors for Adaptive Traffic Signal Control: An Empirical Bayes Before-After Study, Tang et al., 2020

Star Quality Rating:3 Stars  [View score details]
Rating Points Total:100
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.042
Crash Reduction Factor (CRF)
Value:-3.1  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:4.2
Crash Type:Rear end
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:Roadway/roadway (not interchange related)
Intersection Geometry:3-leg,4-leg
Traffic Control:Signalized
Major Road Traffic Volume:Minimum of 3706 to Maximum of 66387 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:Minimum of 111 to Maximum of 34716 Annual Average Daily Traffic (AADT)
Average Major Road Volume :23080 Annual Average Daily Traffic (AADT)
Average Minor Road Volume :7321 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used:2005 to 2018
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):1130 crashes after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Feb 25, 2021
Comments:This CMF is for ATSC intersections with at least three years of after period data.