Traffic signs, like "stop" and "yield," would have to be replaced by 2015, and all others by 2018.

But Corker and Alexander say this is a costly burden, and have proposed allowing state and local governments to install reflective signs whenever a sign is about to be replaced at the end of its normal life span.

"Obviously, everyone wants our roads to be as safe as possible, but the arbitrary deadlines assigned by Washington amount to an unfunded mandate on local governments at a time when they can least afford it," Corker said. "Instead of asking local governments to shell out $50 million, it seems like a much more reasonable approach to replace road signs when they need to be replaced instead of an arbitrary deadline assigned by some Washington bureaucrat."

Corker and Alexander noted that Tennessee Governor Bill Haslam (R) signed a resolution on May 30 calling on Congress to fully fund the FHWA's mandate on signs.