CMF / CRF Details

CMF ID: 9380

Implement truck lane restrictions

Description: TLR prohibit semi- trucks (trucks) from using the left-5 most freeway lane, or inner lane, except in passing or emergency maneuvers.

Prior Condition:  Roadway without Traffic Lane Restrictions

Category: Roadway

Study: Safety Performance of Truck Lane Restrictions in Texas: Empirical Bayes Observational Before-After Analysis, Das et al., 2018

 
Star Quality Rating:2 Stars  [View score details]
Rating Points Total:65
Crash Modification Factor (CMF)
Value:1.17
Adjusted Standard Error:
Unadjusted Standard Error:0.36623
Crash Reduction Factor (CRF)
Value:-17  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:36.623
Applicability
Crash Type:Truck related
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types:Not specified
Street Type:
Minimum Number of Lanes:8
Maximum Number of Lanes:8
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:Divided by Median
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:
Traffic Volume:
Average Traffic Volume:
Time of Day:All
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
Municipality:Dallas-Fort Worth
State:TX
Country:
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (sites):16 sites before, 16 sites after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Oct 27, 2018
Comments:This CMF is for large truck involved fatal and injury crashes on eight-lane roadways. The number of crashes in the after period were not reported in this study, however, they have been recorded as 300 to give 10 points as a beneift of doubt for one or more of the following: (1) number of miles/sites in the reference/treatment group, (2) number of crashes in the references/treatment group, (3) reporting AADTs for the aggregate dataset but not for the disaggragate dataset used for CMF development.