Bridges

Vehicle crashes have been identified as the most critical bridge risk in New Zealand, contributing to more bridge related deaths per annum than floods, earthquakes, vehicle overload and deterioration combined. In recent years the Australian and New Zealand governments have aligned with the "Vision Zero" movement, taking a "Safe Systems" approach to Road Safety with a vision of zero deaths on the road by 2050. Waka Kotahi NZ Transport Agency have launched the "Road to Zero" campaign, targeting a 40% reduction in road deaths and serious injuries by 2030. Similarly in Australia, the National Road Safety Strategy is targeting a 50% reduction in fatalities and 30% reduction in serious injuries by 2030. Despite the relatively small proportion of the road network that is supported by bridges, they represent a significant hazard within the roadway.

Given their disproportionate contribution to serious crashes, Waka Kotahi commissioned a study into bridge crashes and barrier performance. The study indicated that from 2010 to 2020, 11-12% of road fatalities and serious injuries occurred on a bridge or immediate bridge approach. While there has been a significant focus on improving the safety of new bridges and upgrading highway safety systems; older bridges with substandard barrier systems and narrow widths have been progressively becoming more out of context with their surrounding highway environment. As such, a targeted focus on bridge safety improvements is needed to achieve "Vision Zero". This paper outlines the findings from Waka Kotahi's study including the degree of influence that key factors have on the likelihood and consequence of crashes at bridges. The details of a consistent nationwide bridge barrier risk screening tool are described, along with examples of effective retrofit solutions that are being employed to reduce risk and achieve the "Road to Zero" objectives.