King County trolley bus wired for success

About 18 percent of Seattle commuters ride trolley buses

89 percent of Metro riders own a car, but commute by bus

Over 57 million commuters use Metro Transit per year

Challenges

Metro needed to evaluate several vehicle alternatives to its aging trolley bus fleet ahead of its procurement of replacements.
Primary replacement options included electric trolley buses (taking power from the overhead contact system), fuel-cell powered electric buses, hybrid diesel-electric buses, and motor buses burning compressed natural gas.
Because of Seattle's steep terrain, a full-scope capability assessment was needed to determine the most effective candidate vehicle.

Surveyed six systems that continue to operate trolley bus fleets in North America: Boston, Philadelphia, Dayton, San Francisco, Seattle, and Vancouver.
Prepared an extensive vehicle system and bus technology assessment, evaluating trends and further developments in multiple technologies including diesel-generator and battery based auxiliary power units (APUs).
Compiled all research and analysis into a project report detailing environmental comparisons, consideration of federal funding sources, and a total life-cycle cost analysis of vehicle alternatives.
Concluded two technologies merited further study: electric trolley buses equipped with battery APUs and hybrid diesel-electric buses (which may require modification to the drive train system to climb steep hills).

Leveraged insights from the project report to inform Metro’s procurement of new electric trolley buses, generating significant environmental advantages of electric propulsion in a region largely dependent on hydropower.
Successfully mitigated risk of using wireless buses on Seattle’s steeply graded transit lines.
Based on the study results, Metro ordered 141 battery-powered New Flyer Xcelsior trolley buses in June of 2013, rolling out the first in its fleet to have a low-floor design, wheelchair ramps (instead of lifts), air conditioning, and auxiliary power units.