CMF / CRF Details
CMF ID: 8496
Change right-turn lane geometry to increase line of sight (intersection level)
Description: Changes made to study approaches include: sharpening the flat approach angle typical in the traditional design, reducing the radius, adjusting the stop/yield bar position, and/or modifying the corner island to improve safety by increasing the line of sight of approaching through traffic.
Prior Condition: Traditional right-turn lane design
Category: Intersection geometry
Study: Effectiveness Evaluation of a Modified Right-Turn Lane Design at Intersections, Schattler et al., 2016
Star Quality Rating: | [View score details] |
Rating Points Total: | 120 |
Crash Modification Factor (CMF) | |
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Value: | 0.558 |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 0.089 |
Crash Reduction Factor (CRF) | |
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Value: | 44.2 (This value indicates a decrease in crashes) |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 8.95 |
Applicability | |
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Crash Type: | All |
Crash Severity: | All |
Roadway Types: | All |
Street Type: | |
Minimum Number of Lanes: | |
Maximum Number of Lanes: | |
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: | |
Traffic Volume: | |
Average Traffic Volume: | |
Time of Day: | |
If countermeasure is intersection-based | |
Intersection Type: | Other |
Intersection Geometry: | 3-leg,4-leg |
Traffic Control: | Other |
Major Road Traffic Volume: | |
Minor Road Traffic Volume: | |
Average Major Road Volume : | |
Average Minor Road Volume : |
Development Details | |
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Date Range of Data Used: | 2003 to 2014 |
Municipality: | |
State: | IL |
Country: | |
Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
Sample Size (crashes): | 274 crashes before, 161 crashes after |
Sample Size (sites): | 6 sites before, 6 sites after |
Sample Size (site-years): | 18 site-years before, 18 site-years after |