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’d never heard of grassy tramlines, I love them! I’ve never seen any anywhere, and I’ve been all over Europe, they are either quite rare, or I haven’t been paying attention.
We’ve even got them in Finland and we only have two cities with a tram network. Otherwise I’ve seen them a lot in Germany and newer systems tend to have them more often than older ones.
We have some small sections of grassy tram lines in Melbourne (Australia) but I wish we had more.
One problem with grassy lines is that when you need to temporarily use replacement buses (like in cases of issues with the electricity or maintenance, etc.) they can’t drive on the lines and have to take the regular roads with the cars.
At the moment one tram line in my city has been interrupted for a few weeks and that’s how I noticed that the grassy line was making things more complicated for the buses that are used instead.
I think that’s one reason why most cities only put a few sections with grass.
I’d seen quite a few pictures and video of them, but the first ones I actually got to walk around and ride on were in Heidelberg in Germany. The north lines (5, 21, 24, 26) have grassy tram sections.