A large fleet of diesel, hybrid diesel-electric, and natural gas powered buses operate services which typically terminate in the city-centre or at a suburban interchange.

[2] At this time the Adelaide Metro brand was implemented across all transport operators,[3] appearing to the public as a unified network, with common livery, timetable designs and a city Information centre.

In September 2022, the Minister for Transport announced that the final pure diesel bus have been delivered, and that all future deliveries would be hybrid diesel-electric or full electric.

[12] This bus is the first one of its kind operating in Adelaide public transport system after double-decker trolleybuses were removed from service in 1958.

[18] The Adelaide Metro's most frequented route is the O-Bahn guided busway to Modbury carrying around 9 million passengers a year.

Buses leave the track at Paradise or Tea Tree Plaza to continue services on normal roads, eliminating the need for passenger transfer.

Since 2021, Adelaide Metro has worked to improve the signage throughout these various interchanges, with new totem style signs being implemented in all critical locations.

Serco had previously informed the Minister for Transport that it was not willing to continue to operate the bus services for a further five years on the terms contained in the then existing Contract.

Serco had made a submission to the Department of Transport and Urban Planning proposing to operate the bus services in the contract areas on new terms and conditions.

[24] The contracts are in place for an initial eight-year term, from 2 October 2011 to 30 June 2019 with an option to extend for a further four years, subject to government approval.

The negative experience following this latest change of operators reflects the advice given to the Government in 2009, when it was recommended that contracts should be extended by negotiation, rather than re-tendered.

Professor David Hensher, Director of the Institute of Transport and Logistics Studies at the University of Sydney, has commented that while three rounds of competitive tendering in Adelaide had ironed out the cost inefficiencies and lack of service incentives under the previous public monopoly model,all the research on competitive tendering versus negotiated performance-based contracts is showing that one cannot squeeze any more out of the cost efficiency stone after three rounds and the risk of declines in service quality is real if this is pushedIt is not just service performance which is suffering; Government data shows a steady increase in patronage over the first two complete rounds of competitive tendering, followed by a sharp drop-off in the past two years.