The Federal Highway Administration initiated a study to explore the benefits and costs of fully deploying operational strategies and integrating ITS in the large metropolitan area of Seattle. The strategies included in Seattle's Full Operations and ITS Deployment Scenario were identified by consulting with local agencies to identify the overall ITS program planned through the next 25 years. The benefits are contingent on complete deployment of the full operations and ITS deployment scenario. The selected strategies are listed in the following table.
|Arterial Traffic Management Systems||Central Control Signal Coordination|
|Emergency Vehicle Signal Preemption|
|Transit Vehicle Signal Priority|
|Freeway Management Systems||Central Control Ramping Metering|
|Transit Management||Fixed-Route Automated Scheduling and Automatic Vehicle Location|
|Fixed-Route Security Systems|
|Electronic Transit Fare Payment|
|Incident Management Systems||Incident Detection, Verification, Response, and Management|
|Emergency Management Systems||Emergency Vehicle Control Service|
|Emergency Vehicle AVL|
|Traveler Information||Phone- and Web-Based Traveler Information System|
|Kiosk-Based Traveler Information|
|Highway Advisory Radio|
|Dynamic Message Signs|
|Crash Prevention and Safety||Railroad Crossing Monitoring Systems|
|Commercial Vehicle Operations||Weigh-in-Motion and Safety Information Exchange|
|Combination Screening and Clearance|
|Supporting Deployment||Traffic Management Center|
|Transit Management Center|
|Information Service Provider Center|
|Closed Circuit TV and Loop Detectors|
- Overall, vehicle speeds on Seattle's road network increased by less than 1 percent on a daily basis as a result of the ITS deployments.
- The majority of the speed increase was observed on major facilities (freeways, expressways, and major arterials) that served as a focus of a number of the ITS and operations improvements. These speed increases were typically greatest during the congested commute periods.
- Speeds on the regional freeways increased by 1.3 percent and speeds on major arterial roadways increased by 2.4 percent during the afternoon commute period.
- Speed increases observed for some segments of major roadways, such as Interstate 90 near Bellevue or Interstate 5 between Seattle and Tacoma, were more significant, ranging as high as 12%.
- Speed increases observed on minor local streets, which received fewer improvements, and during less congested non-commute hours were generally insignificant. The overall network speed impact was moderated by the less significant impact on the local street system.
Federal Highway Administration
ITS Joint Program Office