CMF / CRF Details

CMF ID: 7685

Change from permissive only to flashing yellow arrow protected/permissive left turn

Description: Change from permissive only to FYA - protected/permissive left turn

Prior Condition:  Permissive phasing

Category: Intersection traffic control

Study: Safety Effectiveness of Flashing Yellow Arrow: Evaluation of 222 Signalized Intersections in North Carolina, Simpson and Troy, 2015

 
Star Quality Rating:2 Stars  [View score details]
Rating Points Total:70
Crash Modification Factor (CMF)
Value:0.592
Adjusted Standard Error:
Unadjusted Standard Error:0.146
Crash Reduction Factor (CRF)
Value:40.8  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:14.6
Applicability
Crash Type:Left turn
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types:Not specified
Street Type:
Minimum Number of Lanes:
Maximum Number of Lanes:
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:
Minimum Speed Limit:35
Maximum Speed Limit:55
Speed Unit:mph
Speed Limit Comment:
Area Type:Not specified
Traffic Volume:
Average Traffic Volume:
Time of Day:
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 7000 to Maximum of 49000 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:Minimum of 600 to Maximum of 17000 Annual Average Daily Traffic (AADT)
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:2003 to 2013
Municipality:
State:NC
Country:
Type of Methodology Used:Simple before/after
Sample Size (crashes):20 crashes before, 12 crashes after
Sample Size (sites):30 sites before, 30 sites after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Nov 01, 2015
Comments:Target crashes are defined as "left-turn same roadway crashes with the left-turner on an approach treated with FYA and occurring during the time of day when FYA is in operation".