BRT ABC is a future bus rapid transit (BRT) system for the southwest Greater São Paulo as a successor of the São Paulo Metro Line 18-Bronze monorail project, cancelled in 2019 by governor João Doria.

The local line will stop by all of the 20 stations and 3 terminals, with medium speed of 19 km/h (12 mph) and headway of 4 minutes during peak hours.

The semi-express line will attend the 3 terminals and 5 interest stations with medium speed of 23 km/h (14 mph) and headway of 3 minutes during peak hours.

The express line will only attend the 3 terminals with headway of 8 minutes and medium speed of 25 km/h (16 mph).

[4][5] On 10 June 2021, desembargador Marrey Uint, from the Court of Justice of São Paulo, suspended, through a temporary lawsuit, the prorogation of Metra's concession alleging, among other reasons, that the period would be beyond the allowed limit (total of 35 years) and the extra permission to operate the 85 lines of intermunicipal buses of the Greater ABC and the construction of the system wouldn't exempt company contract through a bidding process.