CMF / CRF Details
CMF ID: 4113
Improve signal visibility, including signal lens size upgrade, installation of new back-plates, addition of reflective tapes to existing back-plates, and installation of additional signal heads
Description: 4-leg intersections with 3 or 4 lanes on each approach and 50 km/h posted speed
Prior Condition: Smaller signal lens size, old back-plates, no reflective tapes on existing back-plates, and less number of signal heads
Category: Intersection traffic control
Study: Investigating Effect of Collision Aggregation on Safety Evaluations Using Multivariate Linear Intervention Models: Case Study of Signal Head Upgrade Program, El-Basyouny et al., 2012
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 150 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.867 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.052 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 13.3 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 5.2 |
| Applicability | |
|---|---|
| Crash Type: | Nighttime |
| Crash Severity: | O (property damage only) |
| Roadway Types: | Not Specified |
| Street Type: | |
| Minimum Number of Lanes: | 3 |
| Maximum Number of Lanes: | 4 |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | |
| Minimum Speed Limit: | 50 |
| Maximum Speed Limit: | 50 |
| Speed Unit: | km/h |
| Speed Limit Comment: | |
| Area Type: | Urban |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | Night |
| If countermeasure is intersection-based | |
| Intersection Type: | Roadway/roadway (not interchange related) |
| Intersection Geometry: | 4-leg |
| Traffic Control: | Signalized |
| Major Road Traffic Volume: | Minimum of 4637 to Maximum of 51743 Average Daily Traffic (ADT) |
| Minor Road Traffic Volume: | Minimum of 134 to Maximum of 48906 Average Daily Traffic (ADT) |
| Average Major Road Volume : | 20876 Average Daily Traffic (ADT) |
| Average Minor Road Volume : | 11014 Average Daily Traffic (ADT) |
| Development Details | |
|---|---|
| Date Range of Data Used: | 1999 to 2004 |
| Municipality: | British Columbia |
| State: | notusa |
| Country: | Canada |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 1348 crashes before, 786 crashes after |
