Turning one of New Zealand’s most dangerous roads into a safer and enjoyable journey for drivers

State Highway 58 Safety Improvements—Construction Stages 1 and 2A

State Highway 58 had been identified as the second worst performing highway in New Zealand, with a history of severe crashes causing serious injury and death—something had to be done. Waka Kotahi, the New Zealand Transport Agency, engaged us to help provide better visibility, more safety features, and a less demanding journey.

Several factors made the road difficult to drive, including poor-visibility corners, elevation changes, and a challenging route, with many heavy vehicles in the traffic mix. Frequent lane closures for accidents and ongoing, increasingly frequent road repairs added to driver frustration. After a careful analysis of the road’s geography and traffic patterns, our solution saw challenging bends modified or eliminated, slow vehicle passing lanes installed on uphill sections, and roadside safety barriers and traffic cameras fitted. Anticipating an increase from 15,000 to 20,000 vehicles per day, the redesigned road accommodates more traffic, more safely.

Other works to enhance the longevity of the road included stabilisation work to new cut slopes with roadside walls, reducing the risk from future rock falls. Retaining walls below the road reduced future landslip risk and protected essential infrastructure. We also added facilities to assist with fish passage and 8,300 new plants to offset vegetation loss from the adjacent regional park. The changes improve access for the local community, trip times are reduced, and it’s predicted death and serious injury crashes will reduce by 70 percent.