There were all sorts of behind-the-scenes factors at work:
At the time of closure the Bath trams had been bought up and owned by the Bristol bus company. Tram fares were fixed by the council, but bus fares were not; the bus company was able to set higher fares if they replaced trams by buses.
It suited the bus company to standardize its equipment by running its buses on the tram routes. Buses were also much cheaper to replace than the tram cars.
The tramway company had to maintain a lot of the road surface, by act of parliament at their own expense, buses did not.
Because of the enforced low fares, and the fact that the law enabled the council to take over the tram at any time which discouraged investment, the tramway company didn’t have a track and equipment replacement programme in place, so by 1939 a lot of the track was badly in need of replacement.
Another factor was that the elite who tended to “run things” were also car drivers and were annoyed with being stuck behind cars. They imagined that if they could get rid of the pesky trams, quite naturally they could drive faster. But the opposite happened and they got bogged down in traffic jams caused by all the other cars that the ex-tram people got hold of.
When the tram was replaced by modern buses, their usage droped immediately by 1/3