Complete Corridors

The basic idea of a Complete Corridor evolves around providing a variety of travel choices, and then using technology to increase efficiency and pricing to balance use of the roadway network. The backbone of a multimodal transportation system is smart and connected highways and major roads that are managed in real-time to ensure people and goods move efficiently and safely. Locally, Complete Corridors provide dedicated space for cars, transit, shared mobility, bikes and pedestrians, commercial vehicles, and other Flexible Fleets.

Complete Corridors are most effective when applied systemwide to regional highways and major roads that connect to Mobility Hubs and support the Transit Leap and Flexible Fleets. The Next OS allows for a seamlessly managed system of Complete Corridors across jurisdictions and modes to create the best user experience. Complete Corridor solutions can adapt to changing conditions and manage roadways to achieve specific goals and objectives over time.

Download an informational flier about Complete Corridors (English | Español).
View the 5 Big Moves glossary of terms (English | Español). 

Complete Corridors

Complete Corridors Webinar

On June 26, 2019, SANDAG hosted a webinar about features and anticipated benefits of Complete Corridors with industry experts Ben Sumers from McKinsey & Company and Jonathon Hart from CDM Smith. View the webinar recording and explore how technology, policy, and connected infrastructure can lead to less highway congestion while continuing to grow as a region. Closed captions are available in English and Spanish.

View responses to Frequently Asked Questions (FAQs) from this webinar and learn more about the 5 Big Moves webinar series.


  • Managed Lanes

    Complete Corridors include a connected network of Managed Lanes that are designed to give priority access to transit, carpool, and vanpool users and include congestion pricing for people willing to pay for shorter travel times.

  • Active Transportation and Demand Management (ATDM)

    Complete Corridors are actively managed using technology and data analytics to optimize the roadway network and move people more efficiently by active routing, lane assignments, variable speeds, advanced warnings about stopped or slow traffic, and pricing adjustments based on changing conditions and how many people are using parts of the system. ATDM also provides real-time travel information to help people decide how, where, and when to travel.

  • Connected vehicles and infrastructure
    Complete Corridors include smart signals to improve traffic flow and feature high-speed communications networks that allow connected vehicles, smartphones, and smart roads to communicate and share data with each other to reduce congestion, collisions, and traffic delays.
  • Priority for transit, active transportation, and shared mobility

    Dedicated lanes combined with smart intersections give priority to transit, bikes and pedestrians, and other shared mobility, making them faster, safer, and more reliable. 

  • Curb management
    Curb space can be managed to accommodate multiple uses – including passenger pick-up and drop-off, commercial deliveries, bikes and pedestrians, transit, and Flexible Fleets – at different times and based on demand.
  • Zero-Emission Vehicle (ZEV) infrastructure
    Public charging and hydrogen fueling stations help support the shift to plug-in electric vehicles and fuel cell electric vehicles.

Complete Corridors

Anticipated Benefits

Complete Corridors offer an integrated approach that emphasizes providing transportation improvements for the benefit of the whole system and all modes of travel.

  • Increased roadway capacity
    Managed Lanes like those in the Interstate 15 corridor encourage use of high occupancy vehicles, which helps increase capacity and reduce congestion.
  • Reduced congestion and air pollution

    With fewer traffic jams and idling, more zero emission vehicles, and a larger share of the population using transportation alternatives, Complete Corridors can help reduce congestion and air pollution.

  • Travel time savings

    ATDM strategies have shown travel time savings improvements of more than 10%. Connected vehicles could increase overall network capacity by 10-25%, according to the U.S. Department of Transportation’s Beyond Traffic 2045 Report

  • Increased transit ridership

    Congestion pricing resulted in significant shifts to transit in London and Stockholm. Bus delays in central London dropped 50% after pricing was introduced and there was a 7% rise in bus ridership. In Stockholm, daily transit use increased by 40,000 riders, and ridership on inner-city bus routes rose 9%.

  • Improved safety
    Active transportation demand management strategies have shown promise in reducing crashes (up to 30%) and dangerous driving maneuvers (up to 80%). During natural disasters or other emergency situations, active management of the transportation system can ensure that traffic is rerouted to avoid dangerous driving conditions and optimize roadway use during evacuations. Dedicated spaces for bikes, pedestrians, and micromobility also improve safety for these modes.
  • Maximize existing infrastructure
    Complete Corridors maximize the use of existing roadways. Experience and research have demonstrated that expanding roadways ultimately leads to more traffic and greenhouse gas emissions. For example, the 26-lane Katy Freeway in the Houston area is the widest freeway in North America. This $2.8 billion mega-project was intended to alleviate severe traffic congestion, but congestion actually worsened and travel times increased 30% during the morning commute and 55% during the evening commute.

Success Stories and Related Links

  • Oregon’s 217 Active Traffic Management (ATM) project resulted in 7% reduction in average travel time, and travel time reliability improved by 50% while traffic volumes increased 9%.
  • Collisions on Interstate 5 in Washington State decreased 65-75% along a 7.5-mile corridor where an ATM system was deployed.
  • In Austin, Texas, use of ATDM and variable speed limits resulted in 17% reduction in air pollution.