Transportation infrastructure accounts for 20% to 40% of all urban land. These systems grossly enable global warming, with transit now representing an outsize 30% of all U.S. greenhouse gas emissions. But for as little as $20,000, cities can convert streets, highway underpasses, parking lots, and more into urban oases that encourage people to get the hell out of their cars.

The American Society of Landscape Architects (ASLA), the professional organization for landscape architecture, has released this short animation that outlines exactly how communities can redesign existing infrastructure to improve the environment and — bonus! — save dough.

Like a lot of progressive urban policy, much of the redevelopment is happening in San Francisco and New York. To wit: Both have ushered in programs to transform underused streets and sidewalks into “parklets” — mini parks flush with trees, plants, chairs, and tables that give wary urbanites a place to rest and recuperate. That persuades more folks to travel by foot (in SF, one parklet bolstered pedestrian traffic by 37%), which, in turn, can promote shopping and boost the local economy. The up-front cost: Less than $20,000.

The video has lots more great suggestions, like how to turn underpasses into flourishing parks and rail lines into sexy public catwalks, so make sure to watch the whole thing. Then pass it on to your local Congressman.