The average transit bus travels about 130 miles a day. An electric bus from the company Proterra can drive 146 miles, on one electric charge. As battery prices continue to fall and state mandates to cut pollution become more pressing, many cities around the U.S are starting to replace their fleets of gas-guzzling buses with electric and hybrid buses. In fact, electric buses are expected to account for 5 percent of new purchases this year. What makes an electric bus even more appealing is that it can save transit companies around $250,000 to $300,000 over the 12-year life of a bus. With electric buses, city streets will be cleaner and quieter.