CMF / CRF Details

CMF ID: 4702

Convert high-speed rural intersection (4 leg) to roundabout

Description: Convert a high speed rural 4 leg intersection into a roundabout

Prior Condition: 4 leg intersection

Category: Intersection geometry

Study: A Statistical Analysis and Development of a Crash Prediction Model for Roundabouts on High-Speed Rural Roadways, Isebrands, 2012

 
Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.4
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value: 60   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Applicability
Crash Type: All
Crash Severity: A (serious injury),B (minor injury),C (possible injury)
Roadway Types: Not specified
Number of Lanes: 2
Road Division Type:
Speed Limit: 40-65 mph
Area Type: Rural
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: Roundabout
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume : 14000 Annual Average Daily Traffic (AADT)
Average Minor Road Volume : 5600 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used:
Municipality:
State: KS, MD, MN, OR, WA, WI
Country:
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (site-years): 5 site-years before, 5 site-years after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: May-01-2013
Comments: