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Zero-emissions fleet

Our future is electric!

With a target date of 2035, King County Metro is transitioning to a 100% zero-emissions fleet powered by renewable energy. Metro is leading the transit industry—and the country—as an early adopter of a battery-electric bus fleet.

Read the transition plan

Battery-electric bus

The Metro bus that's rechargeable!

Metro is preparing to put its next generation of battery-electric coaches on the road, continuing our transformation to a zero-emissions fleet coaches by 2035. Unlike our electric trolley buses, these heavy-duty battery-electric buses don’t need an overhead wire to keep going. We can just charge and go!

About the fleet

Our next generation fleet will have both 60-foot and 40-foot buses. The 60 ft coaches are able to travel approximately 140 miles on a full charge and accommodate a full passenger load. The 40-ft coaches are able to travel approximately 220 miles when charged.

The next generation buses join a fleet in which all our coaches are either fully hybrid (diesel-electric) or zero-emission (electric trolleys and battery-electric). Metro is committed to building the charging infrastructure to support a zero-emission fleet as it makes the transition to purchasing only zero-emission buses beginning as early as 2023 or 2024.

Electric trolley bus

The current generation of electric trolleys offer many benefits for our passengers, our community and our planet.

Good for riders

  • Ability to go “off wire” means the bus can get around problems on the road and keep you moving!
  • Passengers can open the backdoor when the bus is at a stop—no need to call out to the driver
  • More seats and standing room make the trip comfortable for more people per ride!
  • Air conditioning keeps everyone cool.
  • Low floor makes it easier and safer to get on and off.

Good for neighborhoods

  • No exhaust equals cleaner air.
  • Quiet operation eases the noise of city streets and neighborhoods.
  • Lighter weight so there's less impact on the roads.

Good for the environment

  • These energy-efficient all-electric vehicles use 30 percent less energy than existing trolleys.
  • Zero-emissions help fight climate change.
  • Regenerative braking sends energy back into the trolley electrical system.


  • 2004

    (Completed) Metro is one of the first public transit agencies to adopt diesel hybrids.
  • 2015

    (Completed) Purchases new electric trolley fleet of 174 zero-emissions trolley buses.
  • 2016

    (Completed) Pilots three battery-electric fast charge buses on routes 226 and 241.
  • 2017

    (Completed) Commits to move to a 100% zero-emissions bus fleet powered by renewable energy.
  • 2018-2019

    (Completed) Leases and tests 10 battery-electric buses from three manufacturers.
  • 2021

    (Completed) Metro orders 40 battery-electric buses with a 140-mile range for service out of South Base.
  • 2022

    (Current) Metro commissions a charging test facility at South Base serving the new 40 bus fleet using equipment from three different manufacturers.
  • 2024

    Metro plans to order 120 battery-electric buses.
  • 2025

    Metro plans to open Interim Base at South Campus, fully electrified to operate a 120 bus fleet.
  • 2027

    Opens a new South Annex Base, fully electrified to operate an additional 250 battery-electric bus purchase.
  • 2028-2035

    Construct charging infrastructure at six bases and across system for on route layover. Replace the remaining hybrid bus fleet.
  • 2035

    Metro's goal for operating a 100% zero-emissions fleet of fixed-route buses.


A zero-emissions fleet benefits the community, riders and employees by eliminating greenhouse gas emissions and improving the quality of our air. Additionally, the program aligns with broader King County equity and social justice goals around the Strategic Climate Action Plan.

Metro operates a fleet of over 1,400 buses. Currently, there are 185 zero-emissions buses, which includes 174 electric trolley buses that use overhead wiresand 11 (40-foot) battery-electric buses with charging stations at the Bellevue Base and Eastgate Park-and-Ride.

In 2022, an additional 40 battery-electric coaches are set to start arriving to join the Metro fleet. Produced by New Flyer, both the 60-foot and 40-foot vehicles can travel 140 miles on a full charge, tested to carry a full passenger load.

There are two main types of charging methods: fast charging and slow charging. Fast charging, also referred to as in-route or opportunity charging, allows buses to be charged in minutes between routes and before returning to the base. Slow charging, also referred to as overnight charging, is longer and takes place at bases with charging infrastructure.

Metro is celebrating the opening of a battery-electric charging location in Tukwila that will be the initial home of our battery-electric coaches.

Metro joined only a handful of large transit agencies in the U.S. that have a fleet that does not include fully-diesel coaches with the retirement of the last diesel-only coaches in 2020.

As Metro transitions to our zero-emissions future, we are also trying to ensure that we get value out of the existing fleet of diesel-hybrids, so they will continue to be in use while we develop the infrastructure needed to support our battery-electric coaches.

Metro will phase 40 zero-emissions buses into operations, starting in 2022 at our South Campus in Tukwila. The expansion will continue with a new base with charging infrastructure for 120 battery buses in 2025 and a base for 250 battery buses completed in 2027.

At launch, chargers will be located at bus bases but future enroute chargers are also expected to be deployed, allowing battery-electric bus service on longer routes. All chargers will be a mix of high power and low power, with most chargers being low power and used for overnight charging to manage the electrical load as well as lower costs.

Our 60-foot and 40-foot coaches are tested upon delivery. The 60-foot coaches are able to travel approximately 140 miles on a full charge when loaded to approximate a full passenger load. The 40-foot coaches are able to travel approximately 220 miles when charged.

Metro is working closely with local utilities to site and plan our infrastructure as well as seeking partnerships with private companies and other transit providers to ensure our infrastructure needs can be met in a cost-efficient way.

The electrical infrastructure required to support battery-electric buses, including switchgears and transformers, is already deployed in other high electric-usage industries, including hospitals, large buildings and server farms. Metro has worked with Seattle City Light on a resiliency study of the feeders to the interim base to ensure power needs can be met.

In 2017, Metro made the commitment to begin the large-scale transition of zero-emission battery-electric buses in south King County first to serve BIPOC, low-income and limited-English speaking communities that have disproportionately suffered the brunt of health impacts from air pollution and are on the frontlines of climate change.

Metro is ready to move forward with the next generation coaches that are going into service in 2022. Along with future deployment of on-route charging at strategic locations, the current generation of battery-electric buses are able to meet Metro’s service needs from South Campus. Metro will continue to investigate new technologies that emerge as we proceed with our transition to a complete, zero-emissions fleet.

Additional resources

King County's Strategic Climate Action Plan (SCAP)

King County's Strategic Climate Action Plan (SCAP) serves as a comprehensive five-year strategy aimed at addressing climate change throughout all aspects of County operations. This plan entails a collaborative effort involving King County, its partnering cities, other organizations, communities and residents. The SCAP provides a clear outline of King County's primary objectives and commitments related to climate action, ensuring transparency and accountability in their efforts to combat climate change.

Battery-Electric Bus Implementation Report (PDF)

The report outlines the steps needed to transition to a zero-emissions bus fleet, which include procuring 120 battery-electric buses in 2020, constructing new facilities, setting charging standards, partnering with utilities and training the workforce to operate and maintain these eco-friendly buses. The transition aims to combat the climate crisis and improve social equity by concentrating on areas with high pollution levels, ultimately achieving a 100 percent zero-emissions fleet by 2040.

Metro is transitioning to a zero-emissions bus fleet (PDF)

This document provides a summary of Metro's transition to a zero-emissions bus fleet. It includes an overview of the major electrification investments needed, priorities for 2021-2022 and a timeline of planned capital investments.

Metro's report on Feasibility of Achieving a Carbon-Neutral or Zero-Emissions Fleet (PDF)

This report is a response to a request from the King County Council regarding Motion 14633. They are interested in confirming if it's possible to achieve either a carbon-neutral or a zero-emissions Metro vehicle fleet. To figure this out, we looked at alternatives to the current practice of using diesel-electric buses and electric trolleys. Our assessment considered service needs, costs, necessary supporting systems, environmental results and social equity benefits.

Operational Capacity Growth Report

Metro's 20-year Operational Capacity Growth strategy aims to meet the pressing need to expand operations and bus capacity, accommodating present and future service needs, sustainable growth and electric buses. Key areas of focus are Central Campus, South Campus and a new South King County base, with the report providing cost and timeline estimates for these enhancements.

South King County Base

Learn more about the South King County Bus Base expansion project, which Metro embarked on in an effort to meet current and future transit demands of our growing region. The expansion will allow Metro to house and maintain our buses more efficiently and convert to an all-electric bus fleet by 2040.

Seattle Times op-ed by Rob Gannon, Metro's General Manager

Seattle Times op-ed by Rob Gannon, Metro's General Manager