Over 70 per cent of all domestic passenger movements within Australia occur on roads. Driving remains by far the preferred means of transport within cities and for trips up to 400 kilometres. This is resulting in suboptimal energy efficiency and a congestion cost to the economy of $15 billion per year.14 Based on current trends, congestion will increase, imposing burdens on those living in Australian cities, those seeking to move goods through Australian cities and to the national economy. Particular constraints on freeways and highways will emerge, constraining productivity within cities and regions.