Investigating the influence of roads on trunk main repair rates

<p dir="ltr">This work provides the first data-driven evidence that large diameter (≥ 300 mm) water pipes buried under roads and road junctions have higher repair rates than pipes buried away from roads. Repair data for 10,500 km of trunk mains over nine years were provided by two UK water utilities, which were analysed to determine the repair rates for trunk mains not under roads, under roads, and under road junctions. Significance tests showed that for both utilities trunk mains under roads had higher repair rates than those not under roads (81% and 20% higher median repair rates for each utility) and trunk mains under road junctions had higher repair rates than those under roads but away from junctions (44% and 59% higher median repair rates for each utility). In the short-term water utilities should consider these correlations when selecting trunk mains for replacement. Further research is needed to understand the cause of these correlations and develop predictive models that can be used to guide pipe replacement and reduce the number of disruptive trunk main bursts.</p><p dir="ltr">This paper was presented at the 21st Computing and Control in the Water Industry Conference (CCWI 2025) at the University of Sheffield (1st - 3rd September 2025).</p>