CMF / CRF Details

CMF ID: 8655

Convert a T intersection into a continuous green T intersection

Description: The continuous green T intersection is characterized by a channelized left-turn movement from the minor street approach onto the major street, along with a continuous through movement on the major street. The continuous flow through movement is not controlled by the three-phase traffic signal that is used to separate all other movements at the intersection. Rather, the continuous through movement typically has a green through arrow indicator to inform drivers that they do not have to stop.

Prior Condition: Signalized T Intersection

Category: Intersection geometry

Study: Safety Evaluation of Continuous Green T Intersections: A Propensity Scores-genetic Matching-potential Outcomes Approach, Wood and Donnell, 2016

Star Quality Rating: 3 Stars   [View score details]
Rating Points Total: 105
Crash Modification Factor (CMF)
Value: 0.958
Adjusted Standard Error:
Unadjusted Standard Error: 0.106
Crash Reduction Factor (CRF)
Value: 4.2   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 10.6
Crash Type: All
Crash Severity: All
Roadway Types: Not specified
Number of Lanes: 2-8
Road Division Type:
Speed Limit: 15-60
Area Type:
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
Traffic Control: Signalized
Major Road Traffic Volume: Minimum of 8300 to Maximum of 59000 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume: Minimum of 500 to Maximum of 40000 Annual Average Daily Traffic (AADT)
Average Major Road Volume : 30951 Annual Average Daily Traffic (AADT)
Average Minor Road Volume : 9421 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used: 2008 to 2013
State: FL, SC
Country: USA
Type of Methodology Used: 7
Sample Size (crashes): 2339 crashes
Sample Size (sites): 60 sites
Sample Size (site-years): 297 site-years
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Nov-06-2017
Comments: The study used weighted negative binomial regression with the genetic matched data.