The options are how you spend your money. Improving tree density can have more benefits for the same budget spend. If that’s the case, keep my tram gray and let me hear more birds.

Saying sealed pavement is the only alternative is a false dichotomy. Off the top of my head, gravel ballast has been used for centuries.

A quick search shows 30x maintenence costs for minimal drainage benefits.

Civil engineering isn’t one size fits all and I’m sure there are some climates + layouts where this makes sense. But I’d prefer putting that green space somewhere where people can use it and minimize the cost, focus and footprint of transportation infrastructure as much as possible.

But how exactly is it better? Nicer to look at maybe, but there are other materials that can provide drainage and temperature control with better durability and less maintenance.

I’ll be the one to say it: that’s just stupid.

Lifeless monoculture lawns are as big a waste of resources as car centric infrastructure. Doubly so when it’s in a place where humans can’t even walk on it. Triply so when it’s in a spot where it will gum up and corrode the rails it’s trying to hide.