CMF / CRF Details

CMF ID: 9790

Conversion of intersection into multi-lane roundabout

Description: Conversion of intersection into multi-lane roundabout.

Prior Condition:  Two way stop

Category: Intersection geometry

Study: Crash Modification Factors Based on Crash Histories of 148 Modern Roundabouts in Five States, Zhang and Wang, 2017

 
Star Quality Rating:1 Star  [View score details]
Rating Points Total:10
Crash Modification Factor (CMF)
Value:0.79
Adjusted Standard Error:
Unadjusted Standard Error:0.63
Crash Reduction Factor (CRF)
Value:21  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:63
Applicability
Crash Type:All
Crash Severity:All
Roadway Types:Not specified
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:
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Not specified
Traffic Volume:
Average Traffic Volume:
Time of Day:Not specified
If countermeasure is intersection-based
Intersection Type:Roadway/roadway (not interchange related)
Intersection Geometry:Not specified
Traffic Control:Stop-controlled
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:2005 to 2013
Municipality:
State:FL,IN,NY,PA,WA
Country:USA
Type of Methodology Used:Simple before/after
Sample Size (sites):5 sites before, 5 sites after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Oct 27, 2018
Comments:Two-way stop to multi-lane roundabout 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.