RALEIGH, N.C. — Raleigh Mayor Charles Meeker says the state must change its funding formula for new road construction so that areas with more drivers get more money for new construction.

The number of vehicles registered in Wake County has nearly tripled in the past 25 years. In 1980, there were nearly 226,000 registered vehicles; in 2005, the number increased by 187 percent to nearly 649,000.

Over the same period of time, however, the miles of state roads in the county have increased by just 26 percent. That number does not include widening projects.

"It's a very serious situation," Meeker said.

Within the next five years, Meeker predicts chronic congestion in Wake County.

"You can see over a period of time there's going to be congestion and, frankly, gridlock," Meeker said. "So, it's a discouraging picture looking forward."

Late last year, Raleigh voters approved a $60 million transportation bond to widen roads and synchronize traffic lights to help ease some congestion.

"We've got to find solutions, we know we do," said Joe Milazzo, executive director of the Regional Transportation Alliance.

Leaders believe toll roads must become a serious option. They have helped improve the freeway system in several other cities that the Regional Transportation Alliance has studied.

"San Diego is expecting a million new people, a half million new jobs," Milazzo said. "Their traffic 25 years from now will get better than it is today because they are making investments in transportation."

Aside from new roads, Meeker said a few other alternatives could help future congestion, including more urban housing, so people can live closer to work, and other forms of regional transit.

A countywide committee is expected to have a proposal of infrastructure needs for the next several years by spring.