In conjunction with Ken Davidson, Peter developed a road network model that included all major roads in Australia and collated the data required to perform national accessibility analysis. The model allows road projects to be assessed based on the effect that it has on the whole land use/transport system, rather than on a link or corridor basis. The model also allows the creation of a wide variety of performance indicators, including the overall performance of the network, the effects of flooding on the network, the degree to which industry is served, and the level of network development compared to the ideal. The model has been used on a trial basis to test a number of major national projects, including the Outback Highway, and the Pacific Motorway upgrade.