CMF / CRF Details

CMF ID: 237

Convert intersection with minor-road stop control to modern roundabout

Description:

Prior Condition: No Prior Condition(s)

Category: Intersection geometry

Study: NCHRP Report 572: Applying Roundabouts in the United States, Rodegerdts et al., 2007

 
Star Quality Rating: 4 Stars
Crash Modification Factor (CMF)
Value: 0.29
Adjusted Standard Error: 0.1
Unadjusted Standard Error: 0.08
Crash Reduction Factor (CRF)
Value: 71   (This value indicates a decrease in crashes)
Adjusted Standard Error: 10
Unadjusted Standard Error: 8
Applicability
Crash Type: All
Crash Severity: A (serious injury),B (minor injury),C (possible injury)
Roadway Types: Not Specified
Number of Lanes: 1 or 2
Road Division Type:
Speed Limit:
Area Type: Suburban
Traffic Volume:
Average Traffic Volume:
Time of Day:
If countermeasure is intersection-based
Intersection Type: Roadway/roadway (not interchange related)
Intersection Geometry: 4-leg
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:
Municipality:
State:
Country:
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Other Details
Included in Highway Safety Manual? Yes. HSM lists this CMF in bold font to indicate that it has the highest reliability since it has an adjusted standard error of 0.1 or less.
Date Added to Clearinghouse: Dec-01-2009
Comments: Countermeasure name changed from "convert two-way stop-controlled intersection to roundabout" to match HSM