At a Glance
- King County Metro Transit Department
- Project Location(s)
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.