CMF / CRF Details

CMF ID: 10060

Replace TWLTL with raised median


Prior Condition: Two-way left turn lane

Category: Access management

Study: Two-Way Left Turn Lane or Raised Median? A Truck Safety Based Study, Qu et al., 2019

Star Quality Rating: Cannot Be Rated (Insufficient Information)
Crash Modification Factor (CMF)
Value: 0.718
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value: 28.17   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
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: Not specified
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry:
Traffic Control:
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used: 2011 to 2015
State: TX
Country: USA
Type of Methodology Used: Regression cross-section
Sample Size (sites): 100 sites
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jul-26-2019
Comments: CMF reported here is based on limited information from extended abstract.