LEWISVILLE - A tanker truck accident last year caused one of the biggest backups in the history of Interstate 35E, which occurred just north of the Lake Lewisville bridge.

With no way out, people sat in traffic for hours, which became an eye opener for many. Interstate 35E is the only link for 600,000 Denton County people to Dallas, and vice versa. That number is expected to rise to more than one million by 2030.

"Oh, it's real bad when this tanker truck caught fire," said Richard Riley, a Denton County resident. "We were stuck five hours on the other side of the bridge."

The problem led Rep. Michael Burgess (R - TX) to bring top national and state transportation officials together Tuesday to highlight the urgent need to improve and expand Interstate 35E.

"We saw that with the tanker truck explosion," Burgess said. "And imagine what would happen if we had some incident that required us to evacuate the metroplex to the north."

From the State Highway 121 Bypass to FM 2181 and combining both sides, two to four toll lanes would be added, along with new general-use lanes and continuous frontage roads, according to the proposal.

"Interstate 35E, with the traffic congestion going to and from Dallas, they need all the lanes they can get," said Bob Cates, another Denton County resident.

The $4 billion project may mean toll fees, and some pain for nearby business owners.

"I'm told the right of way line will be 30 inches from my front door," said Brian Robertson, who said he will have to move his business, which has been located on the north side of the Lewisville bridge for 10 years.

"You know, at the end of the rainbow there's good," he said. "But while the rainbow is being built, I don't think it's going to be a very pretty situation."

The next step is to figure out who will fund the project, which will either be TxDOT or NTTA. The hope is that toll fees can pay for the $4 billion project. If not, TxDOT will use gasoline tax, money from SH 121 and bond funds from Denton County voters. That decision will be made in September. Construction starts in 2010.

E-mail ddenmon@wfaa.com