King County Trolleybuses Wired for Success


At a Glance

  • Client(s)
  • King County Metro Transit Department
  • Project Location(s)
  • Seattle
LTK-designed railcarEvaluating King County Metro’s Trolleybus Service. 

King County Metro operates one of North America’s largest trolleybus networks.  Its 14 routes operate under 70 miles of two-way overhead wire. Maintenance of the contact system is expensive and could be eliminated with the use of zero-emissions buses.

Trolleybuses have an expected useful life of about 15 years. In anticipation of its next bus procurement, Metro retained LTK evaluate several alternatives:

  • Electric trolleybuses taking power from an overhead contact system
  • Battery-electric buses
  • Fuel-cell-powered electric buses
  • Hybrid diesel-electric buses
  • Motor buses burning compressed natural gas

LTK researched the vehicles in the six cities that operate trolleybuses in North America – Boston, Philadelphia, Dayton, San Francisco, Seattle and Vancouver, BC – and prepared a bus technology and vehicle systems assessment. LTK’s life-cycle cost analysis calculated whether those vehicles would be able to operate on Seattle’s steep hills and considered the use and further development of diesel-generator and battery-based auxiliary power units (APUs).

King County continues to operate trolleybuses, and has begun pilot testing battery-electric buses.