CMF / CRF Details
CMF ID: 9765
Install adaptive traffic signal control
Description: ATSC is a traffic management strategy in which traffic signal timings change, or adapt, based on observed traffic demand. These systems utilize increased detection to continually collect data on observed demand, and signal timings are then re-optimized based on current data.
Prior Condition: Traditional traffic signal
Category: Intersection traffic control
Study: Estimating Safety Effects of Adaptive Signal Control Technology using the Empirical Bayes Method, Khattak et al., 2018
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 100 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.64 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.063 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 36 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 6.3 |
| Applicability | |
|---|---|
| Crash Type: | Multiple vehicle |
| Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
| 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: | Urban and suburban |
| 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 3148 to Maximum of 61581 Annual Average Daily Traffic (AADT) |
| Minor Road Traffic Volume: | Minimum of 900 to Maximum of 19849 Annual Average Daily Traffic (AADT) |
| Average Major Road Volume : | 25275 Annual Average Daily Traffic (AADT) |
| Average Minor Road Volume : | 6461 Annual Average Daily Traffic (AADT) |
| Development Details | |
|---|---|
| Date Range of Data Used: | |
| Municipality: | Pittsburgh |
| State: | PA |
| Country: | United States |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 210 crashes before, 153 crashes after |
| Sample Size (sites): | 41 sites before, 41 sites after |
| Sample Size (site-years): | 146 site-years before, 141 site-years after |
