(CHARLOTTE) -- A new study by AAA Carolinas takes a look at substandard bridges across the state. Spokesman Tom Crosby said it is an issue that is growing.

"I think that we have one of three bridges in the state is rated substandard by federal standards," said Crosby.

He added that a lack of funding is catching up with North Carolina's infrastructure. "The problem is that we've been having a shortfall every year for the last 10 years and that shortfall is in the hundreds of millions each year, so we really are kind of slipping behind.  We had a 3 percent increase in substandard bridges in this reports, which includes the list of 2011 bridges, so it isn't getting better."

The study found that the most substandard bridge in the state is on South Buffalo Creek in Guilford County, which is nearly 60 years old. Number two on the list is I-40 over U.S. 70 in Wake County. NCDOT estimates it would cost approximately $5 billion to replace all substandard bridges. None of North Carolina’s substandard bridges pose currently pose an immediate threat to motorists.