Semi Trailer Drivers drive trucks up to 42.5 tonnes, comprising a rigid truck and a single trailer. The bulk of this work is long-distance, much of it involving deliveries interstate. This is a highly skilled occupation which involves a lot of travel. Drivers can opt to be their own bosses by buying their own rigs, setting up their own business and sub-contracting their services to large transport operators. Many Semi Trailer Drivers begin their careers driving smaller trucks, building up skills and experience before they advance to driving semi trailers.