Skip to main content

City of Seattle implements SCOOT adaptive traffic management

Seattle Department of Transportation (SDOT) has implemented a new adaptive traffic control system at 32 intersections along Mercer Street between 3rd Ave W and I-5, which has been one of the city’s most congested corridors for over 40 years. Developed by the UK’s Transport Research Laboratory, the SCOOT (Split Cycle Offset Optimisation Technique) system coordinates the operation of the traffic signals in and around the corridor to help vehicles move more efficiently. SCOOT works in real-time to reduce delay
May 2, 2017 Read time: 2 mins
Seattle Department of Transportation (SDOT) has implemented a new adaptive traffic control system at 32 intersections along Mercer Street between 3rd Ave W and I-5, which has been one of the city’s most congested corridors for over 40 years.


Developed by the UK’s Transport Research Laboratory, the SCOOT (Split Cycle Offset Optimisation Technique) system coordinates the operation of the traffic signals in and around the corridor to help vehicles move more efficiently.

SCOOT works in real-time to reduce delays and adapt to changing traffic volumes, such as congestion caused by nearby sport or concert events. The system detects cars in each lane at every intersection. It determines traffic levels, predicts the flow of traffic and adjusts the amount of time available to each movement through the intersection. The result is more effective and responsive signal operations. SCOOT provides significant benefits:

• Quicker, more reliable travel times through the network
• Enhanced transit operations
• Reduced overall emissions and fuel consumption
• Effective management of traffic fluctuations due to special events

To assess the how well SCOOT is working, vehicle data is being collected daily and compared to historical averages. Reporting periods include the three-hour morning and evening peak travel times in both the eastbound and westbound directions during the five-day working week. From the data received to date, drivers travelling east during peak times are experiencing a six per cent increase in morning travel time reliability and 38 per cent in the evenings.

“This new system will adjust signal timing based on traffic in and around Mercer in real time. We know Mercer is the busiest corridor in the city,” said SDOT Director Scott Kubly. “SCOOT will help reduce the traffic backups we’ve seen along Mercer and help keep people moving.”

Related Content

  • New York’s Midtown in Motion traffic management system wins ITS America award
    June 6, 2012
    ITS America has recognised the New York City Department of Transportation (NYC DoT) for Midtown in Motion, the sophisticated traffic management system launched last July that uses ITS to ease traffic congestion, improve traffic flow, and reduce greenhouse emissions and air pollution on the city’s most congested streets. Coinciding with the award, NYC DoT announced that it is expanding the system, which currently covers 110-square blocks, to cover 270-square blocks in the city’s most heavily congested neighb
  • ITS instrumental in reducing Texan congestion
    September 4, 2018
    ITS projects in the Houston area have seen costs crunched – and even a system failure has proved valuable in analysing performance. David Crawford reports on developments in the Lone Star state Savings by Texan public agencies are major factors in the recent ITS Texas awards, recognising beneficial initiatives in bridge strike prevention and traffic intersection control. In the first, the Texas Department of Transportation (TxDOT)’s Houston District, covering the state’s most populous city and its surround
  • Siemens names first centre of excellence for intelligent traffic technology
    December 15, 2015
    Siemens has chosen Ann Arbor, Michigan as the company’s first centre of excellence for intelligent traffic technology. Siemens will provide Ann Arbor with its latest innovative hardware and software technology to help expand the city’s smart traffic system infrastructure. Ann Arbor will be among the country’s first real-world implementations of this latest intelligent traffic technology and the partnership will allow the city to continue to modernise and enhance its transportation systems, while enablin
  • Underinvestment in infrastructure threatens economic growth
    January 24, 2012
    The 2011 Urban Mobility Report from the Texas Transportation Institute highlights the dangers of continued underinvestment in transportation infrastructure but also offers some hope in terms of possible solutions