Australia’s Bridge Design Load Model: Planning for an Efficient Road Transport Industry

A new Australian bridge design traffic loading standard for design and construction of Australian bridges was developed. The loading model is expected to set the bridge design standard for the next 25 years. This is an important visionary task, an investment for future improvements in transport efficiency, and an investment for our grandchildren, which was motivated by the increased transport efficiency that this generation has been able to achieve because of the investment of our grandparents. The challenge is to appropriately and effectively provide for the future in a manner that is consistent with the potential benefits and costs. The complexities of a range of traffic and vehicle loading scenarios, vehicle loading practices and enforcement, an infinite variety of bridge spans and forms of construction, and future unknown vehicle and bridge technologies are combined to develop, in collaboration with AUSTROADS and other interested bodies, a recommended bridge design load. The load model represents a substantial increase from the current design load to be one of the heaviest in the world. The load model’s features include a moving load model (M1600) that forms the basis for the application of dynamic load allowances, centrifugal and braking forces, and a stationary load model (S1600). The load model is designed to represent the traffic of the future and hence ensure the future productivity of Australia’s road transport industry. It is a bridge engineering contribution to Australia’s international competitiveness.