It is often assumed that the fact that bus routes are flexible whereas tram routes are fixed is an advantage. This is not really the case as the attached picture and article show ( yes this is a rural scene but the same sort of thing happens in Bath and other cities regularly).
Once a tram has been built it will be there for 40 years and it is in the interests of the operators to run it continuously because the operating costs are very low compared to a bus, and so there are little benefits from curtailing the service. On the other hand buses have very high operating costs so their is continual pressure to cut out off-peak hour services and limit service frequency so that the bus is full.
This is why trams can afford to operate at much higher frequencies than buses. see https://bathtrams.uk/2-minute-tram-service-interval-budapest/
When investors realise that a tram isn’t going to dissappear, this encourages development of housing and offices along-side which creates a positive feedback loop of more development close by and more customers. Thus it is a well known fact that developement is attracted to fixed rail links but not to bus lines.
The Ex Cheif Exec and leader of the consortium that built the Nottngham tram Roger Harrisson stated in a lecture to Bath Trams that he was told by many European companies they would not set up offices unless there was a tram in the city. Nottingham has thrived since the tram was built.
City dwellers may also decide not to own a car.
Spread out housing estates in the countryside are very difficult to service with buses. So the dwellers are forced drive to the local town for shopping creating pollution and congestion. And people who cannot drive or afford a car are seriously disadvanataged e.g. :
“Villagers braved icy roads and snow to gather at Bath’s bus station to show much they value a rural bus service.
Residents of Tunley, Timsbury, Farmborough, High Littleton, Camerton and Hallatrow all want the 179 restored, claiming they have felt cut off by the reduced service.
Around 60 people came together on Saturday to hand over a 1,000-signature petition to First West of England managing director James Freeman and Bath and North East Somerset Council transport chief Mark Shelford.” https://www.somersetlive.co.uk/news/somerset-news/protesters-march-through-bath-bid-2514127″