CMF / CRF Details

CMF ID: 7696

Change from 5-section "doghouse" protected/permissive left turn to flashing yellow arrow protected/permissive left turn

Description: Change from 5-section "doghouse" protected/permissive left turn to FYA protected/permissive left turn

Prior Condition: 5 section doghouse signal

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: 4 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.838
Adjusted Standard Error:
Unadjusted Standard Error: 0.053
Crash Reduction Factor (CRF)
Value: 16.2   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 5.3
Applicability
Crash Type: Left turn
Crash Severity: All
Roadway Types: Not specified
Number of Lanes:
Road Division Type:
Speed Limit: 20-55
Area Type: Not specified
Traffic Volume:
Average Traffic Volume:
Time of Day: Not specified
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 3500 to Maximum of 52000 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume: Minimum of 300 to Maximum of 26500 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): 441 crashes before, 325 crashes after
Sample Size (sites): 156 sites before, 156 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".