Modern trolleybuses with in-motion charging, like Dayton's latest models, will still have substantial batteries for off-wire operation.

Trolley buses cannot be detoured and the infrastructure costs are enormous, as is the cost of even a minor route change.

Battery technology continues to improve in cost, energy density, and charge/discharge rate. There are already systems that use a catenary-like device to "top off" the bus while it is stopped at a bus stop.