Impacts of climate change on marginal nights for road salting

Abstract

Spreading salt on roads costs UK highways authorities millions of pounds each year. As temperatures rise under climate change, the number of nights with freezing temperatures are projected to fall, potentially reducing salting costs. However, this may also mean more nights drop close to freezing, rather than falling comfortably below zero. These ‘marginal nights’ often require a judgement call as to whether salting is required. The analysis presented here considers how climate change is projected to affect the number of marginal nights at nine locations in England in the near-term (2020s). Synthetic temperature timeseries from the UK Climate Projections 2009 weather generator are used to calculate frequencies of marginal nights in the current and potential future climate. The results show a reduction in the average number of marginal nights for all locations under the median estimate of the medium emissions scenario. The full range of results shows that, despite the reduction, marginal nights will still occur, and in some years the frequency will exceed the baseline. This serves as a reminder that, even under a warmer climate, there will be cold periods that require roads to be salted.

Climate change impacts on future driving and walking conditions in Finland, Norway and Sweden

“…Climate models on the other hand give estimates for many decades or even centuries ahead and can simulate different climate change scenarios. Driving road weather models with climate models therefore can help road management and authorities to better plan ahead for the arising challenges and opportunities of road management in the far future (Matthews et al, 2017;McSweeney et al, 2016). Our predecessor study by Toivonen et al (2019) confirmed that the Finnish road weather model RoadSurf (Finnish Meteorological Institute, Kangas et al, 2015) produced accurate historical road temperature estimates for Finland when driven with the cycle 38 of the regional climate model HARMO-NIE-Climate (HCLIM38) and thereby set the grounds for this study.…”

Weather related pedestrians' slip risks and predicting sidewalk slipperiness

“…Climate models on the other hand give estimates for many decades or even centuries ahead and can simulate different climate change scenarios. Driving road weather models with climate models therefore can help road management and authorities to better plan ahead for the arising challenges and opportunities of road management in the far future (Matthews et al, 2017;McSweeney et al, 2016). Our predecessor study by Toivonen et al (2019) confirmed that the Finnish road weather model RoadSurf (Finnish Meteorological Institute, produced accurate historical road temperature estimates for Finland when driven with the cycle 38 of the regional climate model HARMO-NIE-Climate (HCLIM38) and thereby set the grounds for this study.…”

Editorial

“…Authors from universities in China describe research on improving the prediction of real-time traffic flow (Yao et al, 2016) and provide an analysis of the factors affecting driver injury in roadwork zones (Weng et al, 2016). Finally, academic researchers from Spain (García-Pastor et al, 2016) describe a methodology for assessing the true economic impact of improving quality attributes for operators of public transport.This issue of Transport is complemented by a discussion of a recent paper on railway track drainage and by two book reviews of railway and highway texts written by well-respected Greek authors.The lead paper, by McSweeney et al (2016), investigates the potential impact of predicted climate change on the £150 million annual cost of the UK's winter maintenance programme. The focus of their study is on the uncertain, or marginal, nights when temperatures are close to freezing and when winter maintenance managers need to use their expert opinion to decide whether salting is required.…”

“…The effect of climate on road infrastructure is considered in our first two articles. UK-based water specialists and environmental scientists (McSweeney et al, 2016) reflect on the potential impacts of climate change on the future requirement to salt to keep the UK's roads free from ice. Methods of reducing the amount of ice forming on our roads in the first place are the subject of our second paper by highway engineering researchers from the UK industry and academia (Wright et al, 2016).…”

“…The lead paper, by McSweeney et al (2016), investigates the potential impact of predicted climate change on the £150 million annual cost of the UK's winter maintenance programme. The focus of their study is on the uncertain, or marginal, nights when temperatures are close to freezing and when winter maintenance managers need to use their expert opinion to decide whether salting is required.…”