CMF / CRF Details

CMF ID: 2973

Convert an open median to a TWLTL

Description: Convert an open median to a two-way left-turn lane (TWLTL)

Prior Condition: A 4-leg unsignalized intersection has an open median along the major road

Category: Access management

Study: Using a Reliability Process to Reduce Uncertainty in Predicting Crashes at Unsignalized Intersections, Haleem et al., 2010

 
Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 1.45
Adjusted Standard Error:
Unadjusted Standard Error: 0.21
Crash Reduction Factor (CRF)
Value: -45   (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 21.3
Applicability
Crash Type: All
Crash Severity: All
Roadway Types: Not Specified
Number of Lanes:
Road Division Type:
Speed Limit:
Area Type: Not specified
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: Stop-controlled
Major Road Traffic Volume: Minimum of 8955 to Maximum of 66171 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used: 2003 to 2006
Municipality: Orange County
State: FL
Country: U.S.A.
Type of Methodology Used: Regression cross-section
Sample Size (crashes): 176 crashes
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Mar-21-2011
Comments: