DALLAS (CBSDFW.COM) – Drivers may soon have to pick their poison between raising the gas tax or building more toll roads?

Michael Morris is Director of Transportation for the North Central Texas Council of Governments. He and other transportation officials believe a gas tax hike is unlikely. “A region like ours is growing by a million people every ten years,” explained Morris. “We need some ability to continue to build transportation.”

Morris helped craft a letter that was sent to members of Congress who are currently hashing out a transportation bill.

The letter was signed by nearly two dozen transportation agencies and officials nationwide, including the Texas Department of Transportation. “The old saying is the squeaky wheel gets the grease,” said TX-DOT spokesman, Mark Pettit. “With the departments of transportation across the country, everybody is squeaking,” Pettit added.

In the letter, TX-DOT, along with the other agencies urged Congress to give them more freedom to seek alternative means of funding, including adding more toll roads. “The growth is tremendous and our ability to keep up with that growth and have the funding for transportation to do that is necessary,” Pettit explained.

TX-DOT estimates it will cost nearly $500 billion to meet the state’s transportation needs by 2030. Since raising the gas tax is unlikely, toll roads that pay for themselves have become the unpopular alternative.

Morris says North Texas is one of the few regions in the country that currently has that freedom, where managed toll lanes are added to existing freeways.

But Morris is afraid that Congress may snatch that away. “We have that now, but legislation has been tried previously that said we don’t want you to have that flexibility anymore,” recalled Morris. “If we don’t have that, then we don’t have any tools to move forward,” he added.

Senator Kay Bailey Hutchison was one of several members of Congress to receive the letter. The Senator from Texas says she’s not a fan of toll roads.

Instead, Hutchison wants Texas to opt out of the “donor state” program, which sends gas taxes paid by Texans to the federal government which pay for roads in other states. “Why not give TX-DOT the freedom to collect the taxes and build the roads,” said Senator Hutchison. “We don’t need to build roads in other states with our Texas dollars.”

Hutchison says she’s backing a bill that would allow Texas to opt out of the “donor state” program.