The Trolleybus (AKA: electric bus, trolley bus, trolley coach, trackless trolley, trackless tram) is an interesting technology, crossing the rubber-tired bus with the fixed guideway element of overhead caternary wires.
Folks from AORTA have proposed trolleybuses as a lower-cost alternative to Streetcars. The nearest local examples are in Seattle. We also saw trolleybuses in operation on the recent Metro trip to Vancouver, B.C.
On that trip, one of our number remarked that in any city where he had seen trolleybuses, the fleet seemed to be very old.
So my question is why is this technology not seeing more investment? The Streetcar argument is that rails are (arguably) a stronger signal of permance to deverlopers. But isn’t the technology a viable upgrade to diesel buses? Why don’t we see more use around North America? Is there a point at which diesel prices would make electric operation sufficiently cheaper to warrent the capital investment? Are there hybrid-diesel buses that could easily switch to electric-only operation (sort of like plug-in hybrid cars)?