Washington, D.C., has enacted a zero-fare bus bill into law, according to the D.C. Council.

Mayor Muriel Bowser declined to officially approve the bill, which eliminates the $2 fare for all city buses, adds a dozen 24-hour bus lines starting in July and calls for a $10 million investment into other service improvements to the bus lines.

But the council enacted the proposal without the mayor’s signature, making Washington the largest U.S. city to codify a fare-free transit system as the movement takes off nationwide. Kansas City, Missouri, previously the largest city with such a law, made its own transit system zero-fare in 2019, though that city doesn’t have a train system.