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.
I’m surprised nobody pointed out that tyres are extremely polluting:
https://www.theguardian.com/environment/2022/jun/03/car-tyres-produce-more-particle-pollution-than-exhausts-tests-show
CityNerd posted a really good video on this topic a few months ago. https://youtu.be/H6UD9h3hEdk
His videos are primarily US-focused, but I believe this one applies for pretty much any country.
Busses have their uses. Lots of commentor have mentioned the flexibility in setting up / changing routes. But there’s also the flexibility in sizes. You can start a line with a large van or small mini bus and your only overhead is the driver. From there you can scale that up according to demand up to frequently run articulated busses. Meanwhile your minimum investment for tram includes at the very least a not inexpensive track installation.
Don’t get me wrong. If you have the passenger volume that investment definitely pays off. But I don’t like this unnecessary competition between two modes of transport that can be very complimentary to each other and are both better than individual cars.
It would mean that, for very high volume and consolidated bus routes where adding new busses would actually start to contribute to congestion, a city can then decide upon “upgrading” the entire line to a tram. Of course this means changing the infrastructure and lane structure on the involved streets and possibly the layout of the stations
My pet conspiracy theory is that most bus routes are a false compromise sold to voters.
Another problem with light rail would be mountains. Trains don’t like those. On the other hand, cable-cars and cog railway exists and seem to be viable solutions. The city of Lyon even has both and since the cog railway starts on a flat terrain, it is able to switch between both.