CMF / CRF Details

CMF ID: 2108

Change from protected/permitted to protected only left turn signal control during special time-of-day (left turn crashes)

Description: Special time-of-day protected/permitted left turn signal control

Prior Condition:  urban signalized intersection on 1, 2, and 3-lane roads with exclusive left turn lane

Category: Intersection traffic control

Study: Safety of Special Time-of-Day Protected/Permitted Left-Turn Signal Control Display, Ozmen et al., 2009

Star Quality Rating:Cannot Be Rated (Insufficient Information)
Rating Points Total:
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.37
Crash Reduction Factor (CRF)
Value:41.5  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:37
Crash Type:All
Crash Severity:All
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:25
Maximum Speed Limit:45
Speed Unit:mph
Speed Limit Comment:
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:
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:
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Dec 01, 2009
Comments:Only for left-turn related crashes.