If trams are introduced there will be two main differences to the bus services.
Bus routes will have to be changed.
Buses and all other public transport will experience a substantial increase in passenger use
Trams routes are arranged to form a series of spokes radiating from the centre of Bath, this will use the tram to its best advantage as a rapid mass-transit system. Buses, on the other hand, are more flexible and suited to complex routes in places where trams would not be economical. They would run circulating routes which would integrate with the main tram network. This would ensure that people who lived in areas away from the tram routes but already served by bus would not loose their public transport services. It would also keep buses out of the city centre, where pollution as at its worst.
To ensure the maximum benefit for tram operator, bus operator and passenger, the routes, timetables and fares would all heve to be closely integrated.
This has been the experience when tramways opened in towns like Sheffield, Manchester and Wolverhampton. Typically a 30% increase in the use of the other forms of public transport could be expected to be generated as the direct result of a new tram system.