Australia's office employment is centralized in its major cities. Government decentralization policies in Perth and Brisbane seek to move 20 per cent of each city's state public servants out of their central business districts within ten years. A modeling framework is developed to appraise the likely transit system impacts in Brisbane. Two idealized, hypothetical scenarios are advanced to compare city futures in 2031. One scenario mostly moves workers to middle-suburbia on Brisbane's busways. The other mostly moves jobs to outer-suburban commuter rail nodes. These scenarios are both compared to a base case of continued employment centralization. The results suggest both decentralized models provide contra-flow benefits, improved fare-box recovery, and reduced on-board congestion. But decentralization to outer-suburban rail nodes offers disadvantages by raising total car travel. The implications for planning include the need for strong land use policy to direct decentralization strictly to activity centers to achieve benefits for transit systems.