Europe's Grass-lined Railways

Actually not for cutting down on pollution or heat. Instead it´s a (visually pleasing) way to cut down on noise.

Colorado should plant native vegetation. Turf grass obviously ought to be avoided there.

It's beautiful! Perhaps we should blanket train tracks with lawns - at least that'll create a lot of jobs for gardeners. Maybe if we're lazy, we can use astroturf ... Same effect from a distance without all that mowing.

I'm fairly sure those are trams, not trains.

Trams run through busy pedestrian areas all the time. They're just like a bus service, only on rails. They're not high-speed and - while it does happen sometimes - people rarely get hit by them. They soon learn not to dawdle on the tracks!

I really like the idea of having the tramlines go over grass. It would make little difference to the upkeep of the city if they have a lot of grassy areas to maintain.

Here in Colorado, the availability of water tends to be an issue, and I know it's the same in other parts of the country. I don't think this grass thing would be a good idea here.