CMF / CRF Details

CMF ID: 8657

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: 0.92
Adjusted Standard Error:
Unadjusted Standard Error: 0.12
Crash Reduction Factor (CRF)
Value: 8   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 12
Crash Type: Angle,Rear end,Sideswipe
Crash Severity: All
Roadway Types: Not specified
Street Type:
Minimum Number of Lanes: 2
Maximum Number of Lanes: 8
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather: Not specified
Road Division Type:
Minimum Speed Limit: 15
Maximum Speed Limit: 60
Speed Unit: mph
Speed Limit Comment:
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: Regression cross-section
Sample Size (crashes): 1553 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.