CMF / CRF Details

CMF ID: 235

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: 3 Stars
Crash Modification Factor (CMF)
Value: 0.88
Adjusted Standard Error: 0.21
Unadjusted Standard Error: 0.17
Crash Reduction Factor (CRF)
Value: 12   (This value indicates a decrease in crashes)
Adjusted Standard Error: 21
Unadjusted Standard Error: 17
Applicability
Crash Type: All
Crash Severity: All
Roadway Types: Not Specified
Number of Lanes: 2
Road Division Type:
Speed Limit:
Area Type: Urban
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 italics font to indicate that it has a lower reliability than bold font CMFs since it has an adjusted standard error of 0.2 to 0.3.
Date Added to Clearinghouse: Dec-01-2009
Comments: Countermeasure name changed from "convert two-way stop-controlled intersection to roundabout" to match HSM