An all weather Haul Road Upgrade Project was implemented at the OZ Minerals Prominent Hill site in March 2012. The primary objective was to introduce a "traffic light" system identifying the various levels of remediation required and types of depths and material to be utilised. Once designed crossfalls and appropriate drainage were established in conjunction with sub-base, base and wearing course materials the mining haul roads were capable of sustaining traffic during light rain events; thus increasing productivity and vehicle integrity and longevity for sustained periods. The project provided appropriate road systems both in pit and on surface routes to the waste dumps and ROM Pad during rain events. Some $4M per year in recovered productivity has been anticipated by the implementation of this successful project initiative.