CMF / CRF Details

CMF ID: 6158

Conversion of stop-controlled intersection into multi-lane roundabout


Prior Condition: four-leg intersection with stop control on minor

Category: Intersection geometry

Study: Public Opinion, Traffic Performance, The Environment, and Safety After the Construction of Double-Lane Roundabouts, Hu et al., 2014

Star Quality Rating: 2 Stars   [View score details]
Rating Points Total: 45
Crash Modification Factor (CMF)
Value: 2.073
Adjusted Standard Error:
Unadjusted Standard Error: 1.031
Crash Reduction Factor (CRF)
Value: -107.3   (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 103.1
Crash Type: All
Crash Severity: All
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: 50
Maximum Speed Limit: 50
Speed Unit: mph
Speed Limit Comment:
Area Type: Not specified
Traffic Volume:
Average Traffic Volume:
Time of Day: All
If countermeasure is intersection-based
Intersection Type: Roadway/roadway (not interchange related)
Intersection Geometry:
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: 2003 to 2007
Municipality: Bellingham
State: WA
Type of Methodology Used: Regression cross-section
Sample Size (crashes): 168 crashes
Sample Size (sites): 9 sites
Sample Size (site-years): 63 site-years
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Mar-11-2015
Comments: Multilane roundabout on a two-lane undivided roadway. The total entering volume was approximately 15,700 vehicles per day in the before period and 16,100 vehicles per day in the after period.