CMF / CRF Details

CMF ID: 3852

Convert diamond interchange to Diverging Diamond Interchange (DDI) or Double Crossover Diamond (DCD)

Description: Convert a diamond interchange to a Diverging Diamond Interchange (DDI) or a Double Crossover Diamond (DCD)

Prior Condition:  Diamond interchange

Category: Interchange design

Study: Diverging Diamond Interchange Performance Evaluation (I-44 & Route 13), Chilukuri et al., 2011

 
Star Quality Rating:1 Star  [View score details]
Rating Points Total:20
Crash Modification Factor (CMF)
Value:0.54
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value:46  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Applicability
Crash Type:All
Crash Severity:All
Roadway Types:Principal Arterial Interstate
Street Type:
Minimum Number of Lanes:
Maximum Number of Lanes:
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:Urban
Traffic Volume:
Average Traffic Volume:
Time of Day:All
If countermeasure is intersection-based
Intersection Type:Roadway/roadway (interchange ramp terminal)
Intersection Geometry:4-leg
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:Springfield
State:MO
Country:U.S.A.
Type of Methodology Used:Simple before/after
Sample Size (crashes):519 crashes before, 56 crashes after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Jun 04, 2012
Comments:The authors computed the CMF using the crash rates from Table S-5 (p. 18). The before and after sample sizes were taken from Table S-1 (p. 16).