Evaluating the use of rural-urban gateway treatments in New Zealand

Speed has been widely identified as a leading factor in crash occurrence and severity. On rural networks, a key problem is speeding where vehicles transition from a high speed to low speed environment. Research has identified rural-urban gateway/threshold treatments as a speed reducing measure in transition zones. Gateways include the use of signs, road markings and lane narrowing to lower vehicle speeds and improve road safety. Although gateways have been used extensively, e.g. UK and New Zealand, there has been no comprehensive evaluation on their effectiveness in Australia or New Zealand. The main objective of this research was to assess the changes in crash frequency and severity attributable to the implementation of gateways over time. The study involved a before and after comparison of crashes at treatment sites after gateways were installed compared to the general trend at similar sites across New Zealand over the same period. The study was designed as a non-equivalent quasi-experiment using 102 treated and 62 control sites. The results showed that gateways, particularly pinch point gateways, were effective in lowering crashes at rural‑urban transition zones in the New Zealand context.