CMF / CRF Details

CMF ID: 4091

Four to five lane conversion

Description:

Prior Condition:  Four-lane undivided roadway

Category: Roadway

Study: Crash Modification Factor for an Inexpensive Yet Very Cost Effective Safety Improvement: Converting Undivided Four-Lane Urban Roadways to Five-Lane Roadways, Sun et al., 2012

 
Star Quality Rating:1 Star  [View score details]
Rating Points Total:20
Crash Modification Factor (CMF)
Value:0.51
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value:49  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Applicability
Crash Type:All
Crash Severity:O (property damage only)
Roadway Types:Not Specified
Street Type:
Minimum Number of Lanes:4
Maximum Number of Lanes:4
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:Undivided
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Suburban
Traffic Volume:
Average Traffic Volume:22000 Annual Average Daily Traffic (AADT)
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:2004 to 2010
Municipality:Opelousas
State:LA
Country:USA
Type of Methodology Used:Simple before/after
Sample Size (crashes):124 crashes before, 63 crashes after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Nov 01, 2012
Comments:The study segment was a 1 mile section with three signalized intersections and more than 50 driveways. The speed limit on 0.44 miles of the segment (44% of the segment) was reduced from 50 mph to 45 mph after the re-striping project.The cost of re-striping a roadway per mile covering both materials and labor is about $7,105 by the maintenance crew of the LADOTD District Office or $11,450 by outside contract.