Coastal roads have continued to take a severe beating during a summer of high heat and hurricanes like Hurricane Ida, which produced record amounts of rainfall and deadly flooding in the Northeast and the Gulf Coast.

Because these roadways have become increasingly vulnerable, the National Oceanic and Atmospheric Administration (NOAA) has awarded a $1.8 million grant to researchers at the University of New Hampshire to study how and why coastal hazards such as excessive flooding are causing roads to crack and crumble and find ways to protect them.

“We’re trying to better understand the causal links of not only the extreme events but also the gradual changes in sea level rise that can increase the rate of damage to pavement and trigger failures that require major road reconstruction,” said Jo Sias, professor of civil and environmental engineering. “We’re looking at storm surges and wave action but also factors like the amount of time the pavement is under water.”

The focus of the project is to understand the combined hazards of flooding from above and below the road. UNH researchers – and their partners at the University of South Alabama and the Rockingham Planning Commission — will develop a number of hydrodynamic models that can analyze fluids in motion.

They will use new data collected in the field as well as historical information to create high-resolution models to study groundwater and pavement as well as develop a toolkit to help assess the vulnerability of roadways to flooding hazards.

Researchers say that while engineers have investigated these impacts independently, an approach is needed that combines the different effects to better evaluate options when it comes to pavement alternatives.

This information will be valuable to state and town officials to assess the impact of sea level rise on the longevity of coastal roadways and offer practical alternatives for communities to protect the infrastructure.

“Improving coastal roads to withstand the increasing water hazards is important not only for transportation and the people who live there but also for the overall economy and ecosystems in the area,” Sias said.

Taking into account factors such as climate change and shifting weather patterns, the study will focus on two geographically and geologically diverse coastal regions — the northeast coast of New Hampshire and the southeast coast of Alabama.

The grant is part of NOAA’s Effects of Sea Level Rise Program, which is based in the National Centers for Coastal Ocean Science. The program provides a suite of science products to inform coastal managers of local coastal vulnerability and solutions to reduce flood risk.