CMF / CRF Details
CMF ID: 9767
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: | 85 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.6 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.13 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 40 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 13 |
| 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 29340 Annual Average Daily Traffic (AADT) |
| Minor Road Traffic Volume: | Minimum of 3164 to Maximum of 32947 Annual Average Daily Traffic (AADT) |
| Average Major Road Volume : | 18790 Annual Average Daily Traffic (AADT) |
| Average Minor Road Volume : | 18988 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): | 30 crashes before, 13 crashes after |
| Sample Size (sites): | 9 sites before, 9 sites after |
| Sample Size (site-years): | 18 site-years before, 45 site-years after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Oct 27, 2018 |
| Comments: | Applies to crashes within 350 feet of an intersection; SURTRAC adaptive signal control type used |
