ORLANDO, Fla. — The methods used to de-ice roadways cost 22 million American vehicle owners an estimated $15.4 billion in rust repairs over the last five years, according to results from a new AAA survey. The average cost to repair rust-related issues is $500.

In recent years, many states and local transportation departments have shifted from using rock salt to liquid de-icers to combat ice and snow on roadways. These alternatives are more effective because they can be applied before a snowstorm and because they have a lower freezing point. However, these same characteristics can be even more damaging because the chemicals remain in liquid form longer and are more likely to coat components and seep into cracks where corrosion can accelerate.

“While the application of de-icing salts and solutions is critical to keeping our nation’s roadways safe every winter, it’s important that drivers pay attention to warning signs that they vehicle may be suffering from rust-related damage,” said John Nielsen, AAA’s managing director of Automotive Engineering and Repair. “This can be much more than a cosmetic issue, it can also create serious safety issues for drivers by impacting brake lines, exhaust systems, fuel tanks and electrical connection.

Pothole damage becomes another concern when the snow and ice melt. That’s when roadways begin to crumble. According to AAA, nearly 30 million U.S. drivers experienced pothole damage significant enough to require repair 2016, with repair bills ranging from less than $250 to more than $1,000.