JEFFERSON CITY • Missouri's transportation chief on Wednesday told a Senate panel that rebuilding Interstate 70 with tolls would fix just one of Missouri's most pressing highway needs at a time when highway funds plummet.

"This allows us to do a project," said Missouri Department of Transportation Director Kevin Keith. "That's it."

Keith was the first to testify during the first Senate Transportation Committee hearing on a bill that would permit tolls on I-70. The project would be undertaken by a private consortium. Private companies would finance, rebuild and operate the highway.

Tolls would repay the reconstruction and ongoing upkeep of I-70.

The project is expected to cost about $2 billion to $4 billion, depending on how many lanes are added and how many interchanges are rebuilt.

State Sen. Mike Kehoe, R-Jefferson City, is sponsoring Senate Bill 752. His aim is to begin a conversation about how best to rebuild the aging 200-mile stretch of I-70.

While Missouri drivers are not accustomed to paying tolls, Keith said, about 35 states permit tolls — including some surrounding states.

Missouri's annual highway construction budget is roughly $600 million — significantly less than what it was in recent years after the passage of Amendment 3. Passed by Missouri voters in 2004, the amendment shifted gasoline taxes to pay off bonds for highway construction and repair, and moved all revenue from motor vehicle sales taxes to a highway fund over a four-year period.

"We want a toll that is as low as it can be that just funds I-70," Keith said. "We're not looking to take any money out of this project and spend it anywhere else."

Critics renewed their attacks on the proposal to slap tolls on the east-west highway — especially without taking it to Missouri voters.

"We're concerned that doing something like this, without going to a vote of the people, taints the water ... for all the other projects in the state," said Tom Crawford of the Missouri Trucking Association.

Crawford said tolls amount to a tax.

Keith and others who support the toll road idea contend that a project undertaken by a public-private partnership could collect tolls without seeking voter approval.

Ron Leone, executive director of the Missouri Petroleum Marketers & Convenience Store Association, said that his group opposes tolls on I-70 and that they should be subject to a public vote.

"Even if you found a loophole through the (public-private partnership) concept ... we think good public policy demands that it should go to a vote of the people," Leone said.

St. Charles County Executive Steve Ehlmann, through a representative, urged the panel to end the tolled section of I-70 west of Wentzville — and possibly outside that county altogether.