CMF / CRF Details
Convert a T intersection into a continuous green T intersection
Countermeasure ID: 8656
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
| Crash Modification Factor (CMF) |
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| Value: | 0.846 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.114 |
| Crash Reduction Factor (CRF) |
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| Value: | 15.4 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 11.4 |
| Applicability |
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| 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 |
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| Date Range of Data Used: | 2008 to 2013 |
| Municipality: | |
| State: | FL,SC |
| Country: | USA |
| 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 |
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| 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. |