Ottawa, Ontario’s city council recently approved a transit committee’s recommendation for a planning and environmental assessment study for a downtown transit tunnel.

The recommended plan represents the next step toward building a light-rail system through twin underground, two-mile tunnels. Now, preliminary engineering and design work will begin for the light-rail corridor and a maintenance and storage facility, and the city will launch an expedited environmental assessment process, as well as an urban design and transportation study for downtown.

The light-rail system would halve the number of buses traveling through downtown, according to the city. Provincial approval for the $2.1 billion project might be granted as early as May, Ottawa officials said in a prepared statement.