Extreme weather conditions produce substantial strain on numerous facets of the transportation system, with impacts on infrastructure, maintenance and safety. A majority of the states in the US Department of Transportation Region 6 rank among the highest in the nation for the number of federal disaster declarations resulting from severe weather and climate extremes. Also, the diversity of topographic and climatic variations in this region produces thermal and moisture variability that challenge the longevity of existing infrastructure.

As a result, the Southern Plains Transportation Center has identified the area of “climate-adaptive surface transportation” as a research priority. To aid in this endeavor, the South Central Climate Science Center is working to develop regionally specific and spatially extensive datasets that substantially expand climatologies of multiple weather hazards. Furthermore, this data will be used to check, validate and optimize future projections of climate models for the region. This study will benefit transportation research and operations, ranging from traffic safety and risk to infrastructure sensitivities, as well as present future climatic extremes and their trends. 

The initial stage of this ongoing project identified existing meteorological data that extend over the entire Region 6 domain, are high-resolution in time and space, and can provide value-added output that is transportation-relevant. Products are currently under development for two key winter hazards: icy precipitation and freeze-thaw cycles. The impacts of icy precipitation on traffic safety, volume and the economy are well-known, and have been keenly felt over large swaths of the nation’s winters in 2013-14 and 2014-15. Similarly, high number of oscillations about the freezing point of water can be damaging to roadway infrastructure, leading to potholes, scaling and crumbling, particularly coupled with high traffic and improper mix design or construction. Forthcoming products will examine variability of precipitation (extremes, wet days, dry days and their trends) and temperature (cold air outbreaks, warm extremes).

The prospect of increased climate variability and future changes in extremes will have substantial impacts on the transportation sector, and so it is increasingly recognized that climate model data is a potentially useful resource to incorporate in infrastructure planning and hazard risk assessment. Numerous climate projections are presently available; however, not all are able to provide accurate future projections on the regional scale. Work is presently underway to ascertain the reliability of a suite of global climate models for the south central United States. Outcomes from that work, coupled with validations of model versus observed statistics over the historical period, will be used to develop a set of climate scenarios for the region applicable to transportation safety.

In addition to the previously stated benefits, this study aims to develop collaboration between weather and climate researchers, and the transportation community. It is hoped that the developed datasets can be applied to existing and future projects that aim to anticipate and reduce risk, improve resiliency and cost-effectiveness, and foster additional cross-disciplinary partnerships. To that end, the researchers have developed a brief online survey that seeks information from the transportation community on their climate-data needs, including the types of ways that data products and resources can best be disseminated.

This study is being carried out by researchers at the Department of Interior South Central Climate Science Center, which is managed by the USGS National Climate Change and Wildlife Science Center. The center is one of eight that provides scientific information to help on-the-ground managers respond effectively to climate change.