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 approach to data handling aids development of smarter cities
    January 14, 2013
    David Crawford has been to the Irish capital to see a potent memorandum of understanding at work. An imaginative collaboration between the world’s largest IT company and one of Europe’s smaller capital cities is demonstrating a new approach to data handling that could have far reaching implications for urban public transport worldwide. A close working relationship between IBM and Dublin City Council (DCC) dates from 2010.
  • New approach to data handling aids development of smarter cities
    January 11, 2013
    David Crawford has been to the Irish capital to see a potent memorandum of understanding at work. An imaginative collaboration between the world’s largest IT company and one of Europe’s smaller capital cities is demonstrating a new approach to data handling that could have far reaching implications for urban public transport worldwide. A close working relationship between IBM and Dublin City Council (DCC) dates from 2010. The IT giant was looking for a local transport authority as partner for testing IBM’s
  • New approach to data handling aids development of smarter cities
    January 11, 2013
    David Crawford has been to the Irish capital to see a potent memorandum of understanding at work. An imaginative collaboration between the world’s largest IT company and one of Europe’s smaller capital cities is demonstrating a new approach to data handling that could have far reaching implications for urban public transport worldwide. A close working relationship between IBM and Dublin City Council (DCC) dates from 2010. The IT giant was looking for a local transport authority as partner for testing IBM’s
  • Caltrans takes the long view of transport
    October 21, 2016
    Caltrans’ Malcolm Dougherty took time out of his schedule at ITS America 2016 in San Jose to talk to ITS International about current and future challenges. As director of California Department of Transportation (Caltrans) since mid-2012, many would say that Malcolm Dougherty has one of the best jobs in transportation. Caltrans is one of the most progressive and innovative transport authorities, implementing policies to encourage cycling, piloting new