Solar canopies produce green energy and shade buses at MARTA’s Decatur garage.

Here in the United States, public transportation saves 37 million metric tons of carbon dioxide and 4.2 billion gallons of gasoline annually, according to the American Public Transportation Association. Though a greener option than personal vehicles by far, transit agencies still use large amounts of energy, and produce their fair share of waste, in the course of operations.

You’ve already read what we here at Metro are doing to ensure a more sustainable, energy-efficient system today and in the future. With Earth Day as our impetus, we decided to take a look at how other transit agencies across the country are going green. Below, a few examples:

Did you know Chicago Transit Authority headquarters have been LEED Platinum certified since 2012, helped, in part, by their green roof?

Portland’s TriMet holds the title of first U.S. transit agency to use recycled plastic railroad ties instead of steel in an embedded light-rail trackway, including 6,000 on the MAX Yellow Line.

In New York, the MTA‘s sustainability measures include the Grand Avenue Bus Depot and the Corona, Queens Maintenance Facility, where buses and subway cars are washed using rainwater collected in 200,000 and 40,000 gallon underwater storage tanks.

Metro Transit (serving St. Paul and Minneapolis) is operating its Blue Line with 100% wind power for Earth Day.

The Massachusetts Bay Transportation Authority has hosted fifteen community recycling events at their train stations between fall 2012 and spring 2014 to help Bostonians properly dispose of land-banned items such as TVs and other electronics. MBTA’s stations also feature newspaper recycling containers that collected over 700,000 lbs in their first three months of installation.

This month, Bay Area Rapid Transit sought customer feedback on a prototype of their planned “Fleet of the Future.” Besides striving for increased safety, comfort, and sanitation, the new trains will also boast interesting eco-friendly features.

Metropolitan Atlanta Rapid Transit Authority‘s Laredo Bus Facility in Decatur boasts the largest solar PV installation in Georgia, with 4,888 panels generating 1.2MW of green power.

The South Eastern Pennsylvania Transit Authority said its wayside energy storage system was the “first in the world” of its kind when installation began in summer 2012. Several large, sheltered batteries allow SEPTA to capture, store, and reuse its trains’ regenerative braking energy. Extra power can be sold back to the electrical grid to insure demand and stability.