Even if you think what you would say is obvious, please add. This is genuinely something I think makes sense regarding local bus routes given the longevity of light rail and how infrequently routes change, but I also suffer from confirmation bias, so I’m hoping for reasons this would be a terrible idea but obviously would prefer reasons it would be an even more amazing idea than I thought.
We tried in Denmark (Aarhus). Quite expensive, and too many issues. Electrical busses (with dedicated lanes) seems like the better solution,
busbut this is also not cheap.Edit: Spelling
But electrical buses still create an outrageous amount of rubber waste
Don’t let perfect be the enemy of good though, whatever increases ridership and gets people off cars faster is going to have a bigger impact on contamination.
Aarhus is not really a good example of replacing a bus, as it is a rather regional light rail system with a short inner city section. The difficulties they have seen are probably mainly caused by the technical and budgetary choices made during planning.
For Denmark, Odense looks like a better example, that should be successful if they manage to solve the initial challenges, e.g. with noise/vibrations.
As for the longevity that OP is mentioning, the systems in Bergen (Norway) and Tampere (Finland) show how important this is, with huge private investments being made along the lines. A bus line can be gone next year, but rails will stay for at least decades.
What about hydrogen buses?
My guess is that hydrogen busses suffer the same challenges as hydrogen short-distance trucks. Due to an overall low energy efficiency (electrolysis -> compression -> decompression), it makes better sense for long-distance transport.
Buses have the advantage of potentially being able to be refuelled more often