PHOENIX - If generally accepted predictions of global warming come to pass, Arizona's transportation system will have to adapt due to stronger dust storms, snowfall, flooding, forest fires and other factors, experts say.
"If we have increasing high temperatures at airports like Sky Harbor, aircraft can't get enough lift to take off and they only can be used at certain temperatures," said Gregg Garfin, assistant professor at the University of Arizona's School of Natural Resources and the Environment.
Garfin said that the Valley's intense heat already shortens the life of roads. As another example, he noted that smoke from forest fires, which are expected to be more frequent as temperatures increase, can make it difficult for drivers to see.
The Arizona Department of Transportation recently launched a study, funded by a $125,000 grant from the Federal Highway Administration, of how extreme weather fueled by climate change could affect travel on Interstate 10, I-17 and I-19.
"That will allow us to go forward in terms of future planning for projects or potential design changes to infrastructure," said Laura Douglas, an ADOT spokeswoman.
The one-year study will involve not only ADOT but local agencies as well as universities, she said.
"We're really pulling in our key stakeholders like metropolitan planning organizations, the scientific community, the universities, environmental agencies, land development agencies," Douglas said.
Transportation agencies in 15 other states also received the grants.
Aaron Golub, assistant professor at Arizona State University's schools of sustainability and geography and urban planning, said the highways being studied experience many kinds of weather that could be affected by climate change.
"In the south you might have rising temperatures in the summer, worsening dust events," Golub said. "In the north, you might have issues with snow, rain."
Arizona State Climatologist Nancy Selover said the northern part of the state already faces challenges from heavy snowstorms that can trap people for hours.
"We end up with gridlock on the freeway because it's too snowy and the plows can't keep ahead," she said.
According to the American Society of Civil Engineers' Infrastructure Report Card for Arizona, 52 percent of roads are in poor or mediocre condition. Of the 7,835 bridges in the state, 247 are are considered structurally deficient, while 721 are considered functionally obsolete, the report said.
Debbie Niemeier, professor of civil and environmental engineering at the University of California, Davis, said ADOT is doing a good thing by being proactive about changing weather conditions and what that could mean for transportation infrastructure.
"I think this grant gives them a great start," Niemeier said. "It can help them identify areas in infrastructure that then they need to drill down into a little bit deeper to understand what changes or modifications they might need to think about."
Doug Hecox, spokesman for the Federal Highway Administration, said changes or modifications stemming from the ADOT report won't happen until his agency receives the results about a year from now.
"It's the sort of thing where until we see what their results are it's pretty hard for us to say without wild speculation what the effects of their findings will be," he said.
But Niemeier said that study will be good in the long run.
"Anything you can do to improve the reliability of infrastructure to these extreme events is probably going to be cheaper than responding to a massive failure in the infrastructure," she said.
Niemeier said that studying climate change and how it might affect roadways averts the need to spend more money on on repairs after extreme weather strikes.
"By being more proactive, you're actually sort of hedging that you're not going to spend a huge amount of taxpayer money later because you have to react to a big failure," she said.