I've worked in transit. This is not only feasible, it is how it is done.

cannot see why you would want to do it manually. it is done automatically in munchen.

I'm confused, are you suggesting there are places where bus routes change hundreds of times a day?

I can't imagine many reasons a route would have to change on short notice (accident blocking a road?), and in those situations the announcements not quite being right would not be the end of the world.

Buses are often assigned to a route and then leave that route unexpectedly in the middle of the day to service another route (accident, other bus broke down, traffic, subway shutdown etc) , often not starting at the beginning of that route.

Then the bus changes its route number - certainly in the UK I see the drivers punching in the route details when they take over a bus.

Oh right, that makes more sense. I guess you could just keep a record of all the different routes in every bus though? And skip to the right spot manually as needed.