SIX-YEAR FLOW EVALUATION

FLOW is the name given to the transportation system management (TSM) techniques the Washington State Department of Transportation (WSDOT) uses in the Central Puget Sounnd area. The objective of the FLOW system is to enable more efficient use of the transportation network. To meet this objective, WSDOT and other public agencies have implemented, under the FLOW system, a range of techniques, including improved signal systems, park-and-ride lots, high occupancy vehicle lanes, express bus service, carpool and vanpool programs, electronic surveillance stations, ramp meters, closed circuit television monitoring, variable message signs, and Highway Advisory Radio (HAR). This report contains the results of an evaluation of the I-5 FLOW system that was conducted in the fall of 1987. The evaluation includes I-5's ramp metering system, mainline lanes, high occupancy vehicle (HOV) lanes, and analysis of accidents on I-5 during peak hours. The report is in two sections. The first section discusses the major elements and operation of the FLOW system. The second section contains the evaluation described above. FLOW has proven to be an effective traffic management system. In spite of increased demand on the area's freeways due to regional growth, the FLOW system has contributed to improved freeway efficiency. In addition, HOV use has increased, traffic patterns have been more efficiently distributed, and accident rates have decreased. As a result, the FLOW system will continue to be expanded throughout the Central Puget Sound area.

• Corporate Authors:

  Washington State Department of Transportation

  Traffic Systems Management Center, 811 E Roanoke Street
  Seattle, WA  United States  98102
• Authors:
  • Henry, K C
  • Mehyar, O
• Publication Date: 1989-1

Media Info

• Features: Appendices; Figures;
• Pagination: 55 p.

Subject/Index Terms

• TRT Terms: Carpools; Closed circuit television; Crash analysis; Driver information systems; Electronic equipment; Express buses; Guideways; High occupancy vehicle lanes; High occupancy vehicles; Park and ride; Performance evaluations; Radio; Ramp metering; Surveillance; Traffic crashes; Traffic lanes; Traffic signals; Transportation system management; Vanpools; Variable message signs
• Geographic Terms: Washington (State)
• Old TRIS Terms: Highway advisory; Reserved lanes
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors; Terminals and Facilities; I72: Traffic and Transport Planning; I73: Traffic Control;

Filing Info

• Accession Number: 00488657
• Record Type: Publication
• Files: TRIS, STATEDOT
• Created Date: Oct 31 1989 12:00AM