CMF / CRF Details
CMF ID: 9450
Convert to roundabout interchanges
Description: Convert to interchange roundabouts with either a single roundabout or a pair.
Prior Condition: Interchanges without roundabout ramp terminals
Category: Interchange design
Study: Safety Performance Analysis of Roundabout Interchanges in Missouri, Claros et al., 2018
Star Quality Rating: | [View score details] |
Rating Points Total: | 85 |
Crash Modification Factor (CMF) | |
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Value: | 1.288 |
Adjusted Standard Error: | |
Unadjusted Standard Error: |
Crash Reduction Factor (CRF) | |
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Value: | -28.8 (This value indicates an increase in crashes) |
Adjusted Standard Error: | |
Unadjusted Standard Error: |
Applicability | |
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Crash Type: | All |
Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
Roadway Types: | All |
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: | |
Minimum Speed Limit: | 25 |
Maximum Speed Limit: | 45 |
Speed Unit: | mph |
Speed Limit Comment: | |
Area Type: | All |
Traffic Volume: | |
Average Traffic Volume: | |
Time of Day: | All |
If countermeasure is intersection-based | |
Intersection Type: | Roadway/roadway (interchange ramp terminal) |
Intersection Geometry: | No values chosen. |
Traffic Control: | Roundabout |
Major Road Traffic Volume: | Minimum of 2060 to Maximum of 16715 Annual Average Daily Traffic (AADT) |
Minor Road Traffic Volume: | Minimum of 647 to Maximum of 5630 Annual Average Daily Traffic (AADT) |
Average Major Road Volume : | 8186 Annual Average Daily Traffic (AADT) |
Average Minor Road Volume : | 2721 Annual Average Daily Traffic (AADT) |
Development Details | |
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Date Range of Data Used: | 2003 to 2016 |
Municipality: | |
State: | MO |
Country: | |
Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
Sample Size (crashes): | 36 crashes after |
Sample Size (sites): | 5 sites before, 5 sites after |
Sample Size (site-years): | 19 site-years before, 18.5 site-years after |