CMF / CRF Details

CMF ID: 7567

Convert 2 lane roadway to 4 lane divided roadway

Description: Conversion of urban and rural two-lane roadways to four-lane divided roadways

Prior Condition:  2 lane roadway

Category: Roadway

Study: Evaluation of the Safety Effectiveness of the Conversion of Two-Lane Roadways to Four-Lane Divided Roadways: Bayesian vs. Empirical Bayes, Ahmed et al., 2015

 
Star Quality Rating:4 Stars  [View score details]
Rating Points Total:120
Crash Modification Factor (CMF)
Value:0.351
Adjusted Standard Error:
Unadjusted Standard Error:0.089
Crash Reduction Factor (CRF)
Value:64.89  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:8.91
Applicability
Crash Type:All
Crash Severity:O (property damage only)
Roadway Types:Not specified
Street Type:
Minimum Number of Lanes:2
Maximum Number of Lanes:2
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:Urban
Traffic Volume:
Average Traffic Volume:18544 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:2002 to 2012
Municipality:
State:FL
Country:USA
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):34 crashes before, 14 crashes after
Sample Size (sites):41 sites before, 41 sites after
Sample Size (miles):8.578 miles before, 8.578 miles after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Nov 01, 2015
Comments: