Full ITS deployment in Seattle projects vehicle speeds to increase by as much as 12 percent on major roadways.

The projected results of full ITS deployment in a large metropolitan area.

May 2005
Seattle,Washington,United States

Summary Information

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 SystemsCentral Control Signal Coordination
Emergency Vehicle Signal Preemption
Transit Vehicle Signal Priority
Freeway Management SystemsCentral Control Ramping Metering
Transit ManagementFixed-Route Automated Scheduling and Automatic Vehicle Location
Fixed-Route Security Systems
Electronic Transit Fare Payment
Incident Management SystemsIncident Detection, Verification, Response, and Management
Emergency Management SystemsEmergency Vehicle Control Service
Emergency Vehicle AVL
Traveler InformationPhone- and Web-Based Traveler Information System
Kiosk-Based Traveler Information
Highway Advisory Radio
Dynamic Message Signs
Crash Prevention and SafetyRailroad Crossing Monitoring Systems
Commercial Vehicle OperationsWeigh-in-Motion and Safety Information Exchange
Combination Screening and Clearance
Supporting DeploymentTraffic Management Center
Transit Management Center
Emergency Management
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.

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Benefits and Costs of Full Operations and ITS Deployment: A 2003 Simulation for Seattle

Published By: United States Department of Transportation Federal Highway Administration ITS Joint Program Office

Source Date: May 2005

EDL Number: 13977

Other Reference Number: Report No. FHWA-JPO-04-033


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Goal Areas


Typical Deployment Locations

Metropolitan Areas


ramp meters, coordinated signals, signal coordination, centralized signal control, signal synchronization, traffic signals, advanced signal control, signal timing optimization, coordinated signal control, advanced signal controller, traffic signal retiming, retiming, travel time, vehicle speeds

Benefit ID: 2015-01028