Bridges

Australia has regularly reviewed access to the road and bridge network with a view to increasing transport productivity. The current access regime for heavy vehicles has evolved over time with access now controlled by a range of regulations, notices, guidelines and permits for freight vehicles, special purpose vehicles, low loaders and heavy vehicle platforms.

Over time, permits which were once rare, have become relatively common. Heavy vehicles have become larger and faster, suspension systems have evolved and many heavy vehicles are now tracked via GPS and incorporate on-board mass management systems. The bridge network is now being assessed using a limit states approach compared to the working stress approach of yesteryear.

This paper reflects on the history of heavy vehicle access and the issues currently faced by road managers when assessing bridges. The review draws on the experience of assessing Queensland’s bridge network for access by both freight vehicles and permit vehicles (including indivisible loads), in accordance with local and international practice. It shares the insights learned and concludes that it is time for a rationalisation of the method of assessing and managing access to achieve a transparent, robust, consistent and repeatable access regime for heavy vehicles, particularly indivisible loads.