CMF / CRF Details

CMF ID: 4120

Provide split phases

Description: The regular 2 phases of a cycle are split into three phases. Pedestrians receive a "walk" display while the parallel traffic that would normally turn left or right through the crosswalk is held with a left or right red arrow signal and the through movement proceeds on a green signal. After the pedestrian crossing is completed, a red "steady hand" is displayed and the turns are then made on a green arrow signal while the through movement continues to move. Split phase requires dedicated turn lanes since through and turning movements are governed by different signal indications.

Prior Condition: The regular two phases of a traffic cycle are split into three phases. Pedestrians receive a "walk" display while the parallel traffic that would normally turn left or right through the crosswalk is held with a left or right red arrow and the through movement proceeds on a green signal. After the pedestrian crossing is completed, a red "steady hand" is displayed and the turns are then made on a green arrow signal while the through movement continues to move.

Category: Intersection traffic control

Study: The Relative Effectiveness of Pedestrian Safety Countermeasures at Urban Intersections - Lessons from a New York City Experience, Li Chen, Cynthia Chen, and Reid Ewing, 2012

Image: View the countermeasure image.

 
Star Quality Rating: 2 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.44
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value: 56   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Applicability
Crash Type: Angle,Head on,Left turn,Rear end,Rear to rear,Right turn,Sideswipe
Crash Severity: All
Roadway Types: Not Specified
Number of Lanes:
Road Division Type: All
Speed Limit:
Area Type: Urban
Traffic Volume:
Average Traffic Volume:
Time of Day: All
If countermeasure is intersection-based
Intersection Type: Roadway/roadway (not interchange related)
Intersection Geometry: 4-leg
Traffic Control: Signalized
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used: 1998 to 2008
Municipality: New York City
State: NY
Country: USA
Type of Methodology Used: Simple before/after
Sample Size (crashes): 590 crashes before, 103 crashes after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Nov-01-2012
Comments: The major roadway operates as one-way traffic flow. The corresponding change in crashes in the comparison group was a 44 percent reduction in multiple-vehicle crashes. This could be used to adjust the treatment effect to account for other factors not related to the treatment.