A South Portland bus makes its way across the Casco Bay Bridge on Feb. 12, 2020. The city wants to merge its bus service with the Greater Portland Metro at the end of December. Derek Davis/Portland Press Herald

South Portland’s city-run bus service is on track to rejoin the Greater Portland Metro bus system in an end-of-year merger that would save taxpayers $1 million over the next five years.

The City Council unanimously approved the merger Tuesday night, clearing the way for the Metro to assume all operation, maintenance and compliance responsibilities of South Portland bus routes on or about Dec. 29, city officials said in a statement.

South Portland left the Metro in 1983 to operate its own bus system. The Metro’s board of directors is scheduled to vote on the merger Oct. 24.

While service within the city would remain the same after the merger, Metro is expected to propose route improvements in the future. Metro also would carry out planned grant-funded access improvements at several bus stops.

City officials anticipate saving $1 million over five years because the annual assessment to join Metro would be $100,000 to $170,000 less than the annual cost of running the municipal service; Metro would pay South Portland over $252,000 for its buses and other equipment; and the city would avoid future capital costs.

It cost the city $2.5 million to operate the bus service in fiscal 2024, said City Manager Scott Morelli. Minus federal grants and fare revenue, the cost to taxpayers was $806,538. Metro would charge the city $700,000 for the fiscal year starting in July.

As part of the merger, Metro has agreed to hire all South Portland bus drivers; honor their seniority in terms of pay and benefits; and allow them to operate South Portland’s bus routes if they prefer. The municipal service has 10 full-time employees.

All South Portland bus drivers would get a pay raise as Metro employees. The city would have four representatives on Metro’s board and have direct input on any decisions affecting South Portland’s service.