Inspired Projects of 2022: King County Metro Trolley Expansion Strategic Plan


With the year coming to an end, we’re highlighting some of our favorite projects from 2022 that display our dedication to making a difference in the communities we serve. The King County Metro Trolley Expansion Strategic Plan, led by Parametrix Project Manager Mark Yand, received second place in our annual Project of the Year Competition.

Project Overview

King County Metro (Metro) is an innovative force in sustainability. They are leading the transit industry with their conversion to an all-electric rubber tire transit fleet. Metro was already one step ahead with this effort, as they are one of only four transit agencies in the United States that operate an electrified trolley bus system.

Metro’s electric trolley bus was established in 1940. Image courtesy of King County Metro.


This year, Parametrix completed Metro’s first-ever Trolley Expansion Strategic Plan (TESP), which defines a set of potential projects to widen Metro’s sustainable transportation network and improve current operations. Development of the plan focused on identification of existing needs, collaborative identification and screening of potential projects, and creation of cost estimates and operational feasibility assessments.

A Unique Opportunity 

Trolley bus projects are rare. Having the chance to examine options to expand the existing system required creativity and innovation from the project team at every level. Development and maintenance of trolley infrastructure is extremely complicated and operations differ from traditional buses, as trolleys must stay “on track.” Overhead wires, power substations, and visual impacts to the neighborhoods and cities involved all had to be considered.

Additionally, this was Metro’s first ever TESP and Parametrix had the chance to develop it from scratch. Creating a new type of plan can be challenging. Given the intent of this plan to guide future investments, a highly collaborative approach with Metro and the City of Seattle helped us examine each project from a variety of angles and more accurately assess their feasibility and importance to the agency.

Project Significance

This project demonstrates Parametrix’s commitment to supporting the planning and design of transit system improvements for clients moving towards green energy, zero emissions, and sustainable practices.

Scroll to Top