CMF / CRF Details

CMF ID: 9767

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:  Traditional traffic signal

Category: Intersection traffic control

Study: Estimating Safety Effects of Adaptive Signal Control Technology using the Empirical Bayes Method, Khattak et al., 2018

Star Quality Rating:3 Stars  [View score details]
Rating Points Total:85
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.13
Crash Reduction Factor (CRF)
Value:40  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:13
Crash Type:Multiple vehicle
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types:Not specified
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 3148 to Maximum of 29340 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:Minimum of 3164 to Maximum of 32947 Annual Average Daily Traffic (AADT)
Average Major Road Volume :18790 Annual Average Daily Traffic (AADT)
Average Minor Road Volume :18988 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used:
Country:United States
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):30 crashes before, 13 crashes after
Sample Size (sites):9 sites before, 9 sites after
Sample Size (site-years):18 site-years before, 45 site-years after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Oct 27, 2018
Comments:Applies to crashes within 350 feet of an intersection; SURTRAC adaptive signal control type used