CMF / CRF Details
CMF ID: 9771
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
| Crash Modification Factor (CMF) |
|---|
| Value: | 0.6 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.056 |
| Crash Reduction Factor (CRF) |
|---|
| Value: | 40 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 5.6 |
| 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: | 4-leg |
| Traffic Control: | Signalized |
| Major Road Traffic Volume: | |
| Minor Road Traffic Volume: | |
| Average Major Road Volume : | |
| Average Minor Road Volume : | |
| 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 (sites): | 29 sites before, 29 sites after |
| Sample Size (site-years): | 104 site-years before, 99 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. Both SURTRAC and InSync adaptive signal systems The number of crashes in the after period were not reported in this study, however, they have been recorded as 300 to give 10 points as a beneift of doubt for one or more of the following: (1) number of miles/sites in the reference/treatment group, (2) number of crashes in the references/treatment group, (3) reporting AADTs for the aggregate dataset but not for the disaggragate dataset used for CMF development. |
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