CMF / CRF Details
CMF ID: 9664
Implement transit signal priority
Description: Transit signal priority (TSP) is a type of transit preferential treatment implemented at signalized intersections to reduce (bus or urban rail) transit delays by providing extended or early green time 3 to transit vehicles in operation.
Prior Condition: No TSP
Category: Transit
Study: Assessing Effects of Transit Signal Priority on Traffic Safety: Empirical Bayes Before-After Study Using King County, Washington Data, Song and Noyce, 2018
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 140 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.873 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.018 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 12.7 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 1.8 |
| Applicability | |
|---|---|
| Crash Type: | All |
| 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: | Urban |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | Not specified |
| If countermeasure is intersection-based | |
| Intersection Type: | Roadway/railroad grade crossing |
| Intersection Geometry: | |
| Traffic Control: | Signalized |
| Major Road Traffic Volume: | Minimum of 7268 to Maximum of 44576 Annual Average Daily Traffic (AADT) |
| Minor Road Traffic Volume: | |
| Average Major Road Volume : | 26705 Annual Average Daily Traffic (AADT) |
| Average Minor Road Volume : | |
| Development Details | |
|---|---|
| Date Range of Data Used: | 2002 to 2015 |
| Municipality: | King County |
| State: | WA |
| Country: | USA |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 3634 crashes after |
| Sample Size (sites): | 11 sites before, 11 sites after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Oct 27, 2018 |
| Comments: | |
