CMF / CRF Details
CMF ID: 4199
Install dynamic signal warning flashers
Description: Dynamic signal warning flashers (DSWF) provide drivers with advance notice of the phase change. Specifically, the DSWF is linked to the signal and flashers are actuated when the signal is about to change from green to yellow.
Prior Condition: Signalized intersection without advance warning flashers.
Category: Intersection traffic control
Study: Evaluation of Safety Strategies at Signalized Intersections, Srinivasan, et al., 2011
Image: View the countermeasure image.
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 115 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.792 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.079 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 20.8 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 7.9 |
| Applicability | |
|---|---|
| Crash Type: | Rear end |
| Crash Severity: | All |
| Roadway Types: | Not Specified |
| 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: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | All |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | All |
| If countermeasure is intersection-based | |
| Intersection Type: | Roadway/roadway (not interchange related) |
| Intersection Geometry: | 3-leg,4-leg |
| Traffic Control: | Signalized |
| Major Road Traffic Volume: | Minimum of 7500 to Maximum of 99000 Annual Average Daily Traffic (AADT) |
| Minor Road Traffic Volume: | Minimum of 40 to Maximum of 20100 Annual Average Daily Traffic (AADT) |
| Average Major Road Volume : | 27529 Annual Average Daily Traffic (AADT) |
| Average Minor Road Volume : | 4836 Annual Average Daily Traffic (AADT) |
| Development Details | |
|---|---|
| Date Range of Data Used: | 1994 to 2008 |
| Municipality: | |
| State: | NV,VA |
| Country: | USA |
| Type of Methodology Used: | Regression cross-section |
| Sample Size (crashes): | 2651 crashes |
