CMF / CRF Details

CMF ID: 8656

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:95
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.114
Crash Reduction Factor (CRF)
Value:15.4  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:11.4
Crash Type:All
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
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
Type of Methodology Used:Regression cross-section
Sample Size (crashes):848 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.