CMF / CRF Details

CMF ID: 9765

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: 4 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.64
Adjusted Standard Error:
Unadjusted Standard Error: 0.063
Crash Reduction Factor (CRF)
Value: 36   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 6.3
Applicability
Crash Type: Multiple vehicle
Crash Severity: K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types: Not specified
Number of Lanes:
Road Division Type:
Speed Limit:
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 61581 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume: Minimum of 900 to Maximum of 19849 Annual Average Daily Traffic (AADT)
Average Major Road Volume : 25275 Annual Average Daily Traffic (AADT)
Average Minor Road Volume : 6461 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used:
Municipality: Pittsburgh
State: PA
Country: United States
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (crashes): 210 crashes before, 153 crashes after
Sample Size (sites): 41 sites before, 41 sites after
Sample Size (site-years): 146 site-years before, 141 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. Both SURTRAC and InSync adaptive signal systems