Most bus services in Dunedin are subsidised routes set up by the Regional Council, who then call for tenders to operate the routes. A commercial route is a bus service primarily set up to make money for a bus company. Commercial bus routes are run independently of the Regional Council and do not need to meet any of the Council's rules or standards. This is why they sometimes run quite old non-accessible buses, and have slightly different fares.
The bus companies still need to meet all the rules of the New Zealand Transport Agency.