Trams are surely better, but the simple infrastructure and relative simplicity of the drive train make trolley often cheaper than a diesel bus. Trolley buses with a small battery can also deviate from standard lines or bridge small areas between trolley lines.
Trams are surely better, but the simple infrastructure and relative simplicity of the drive train make trolley often cheaper than a diesel bus. Trolley buses with a small battery can also deviate from standard lines or bridge small areas between trolley lines.
Trolleybuses are the best compromise because they can (and in my country/city do) work as diesel/battery buses