The development of climate services to inform decisions about winter maintenance at different timescales

Abstract Snow and ice control programs are critical for the efficiency and safety of transportation systems in all winter climates. Tools that help road authorities plan for, assess, and communicate the relationship between climate and winter road maintenance (WRM) activities are needed. There is increasing evidence that the development of such Climate Services (CS) tools is an iterative, evolving, and long-term process between the producers and users of this climate information, which increases the usability and application of climate science. This paper presents a case study describing the co-production of a climate translation service for a Canadian road authority. The purpose of this study is to: 1) refine an existing Winter Severity Index (WSI) to better understand how winter weather translates into inter-annual variations in WRM activities using publicly available data; 2) apply the index to historical weather observations to assess the magnitude and significance of historical winter weather trends, and 3) apply the index to modelled climate data to project the impacts of climate change on WRM operations in Ontario, Canada. Results indicate that the WSI for Ontario highways has strong fit with maintenance activity, when measured as equipment-hours. Analysis of WRM trends over more than three decades shows that winter severity has increased in some areas and decreased in others. The climate change analysis reveals that winters will experience a reduction in winter severity into the coming century.