A bid by a giant engineering firm to build an $800 million, high-speed toll road around Baton Rouge was rejected Tuesday by a state panel.

The decision came after a consultant hired by the state said the project could cost taxpayers up to $400 million, which backers disputed.

Sherri LeBas, secretary of the state Department of Transportation and Development, said the potential state price tag was “a very big factor” in the vote by the Louisiana Transportation Authority.

“There is just not enough information,” said LeBas, who is on the nine-member panel.

House Transportation Committee Chairwoman Karen St. Germain, D-Pierre Part, chairwoman of the LTA, made a similar point earlier in the meeting. “At the end of the day, we don’t have any extra money for any of these wonderful projects,” St. Germain said.

The state has a $12 billion backlog of road and bridge needs, and general state budget problems that are expected to spark a special session when a new governor takes office in January.

The plan, which was not solicited by the state, was offered by AECOM, a Fortune 500 engineering firm with offices around the world, including Baton Rouge and New Orleans.

The proposal, named the Baton Rouge Urban Renewal and Mobility Plan, or BUMP, would link interstates 10, 12 and 110 and U.S. 61 and U.S. 190 in a new path around often-congested Baton Rouge.

It would have extended 23 miles from I-10 near Pecue Lane in East Baton Rouge Parish, follow a revamped Airline Highway and go across the U.S. 190 bridge to a point on I-10 about 4 miles west of the La. 415 interchange in West Baton Rouge Parish.

Robert Schmidt, a Baton Rouge engineer and the AECOM official who served as point person on the project, said the work would modernize transportation in Baton Rouge, would relieve pressure on I-10 and could open in 2022.

“By highway standards, that is light speed,” Schmidt told the LTA.

But a key dispute surfaced on whether AECOM would absorb all the construction costs, as long assumed, or if the state would have to help with the financing.

Brad Guilmino, chief financial consultant for HNTB, a national consulting firm hired by DOTD, said its economic analysis showed the state would have to come up with $284 million to $397 million for BUMP to become reality.

Guilmino said his firm’s study assumed tolls of about 20 cents per mile — $3.60 for a one-way trip — and that those tolls would remain static.

But Dick Wolsfeld, vice chairman of North American Transportation for AECOM, said his firm projected tolls of 20 cents per mile, then rising to 1 percent above the Consumer Price Index annually to generate a revenue stream that has worked on roads in Dallas and elsewhere.

“This is a great project, and it has a reasonable chance of paying for itself with tolls,” Wolsfeld said.

Later in the meeting Guilmino disputed AECOM’s view of what the tolls would raise.

“This is Baton Rouge,” he said. “There is no tolling here. A lot of those (projections) were on the aggressive side. We stayed more in the middle.”

Schmidt declined comment after the meeting.

What AECOM was touting is called a public-private partnership.

That means a private firm — AECOM or another company — builds the road and contracts with the state to recoup its costs, plus a profit.

The proposal sparked heated views and a split among area officials.

State Rep. Steve Carter, R-Baton Rouge, urged the LTA to move the plan to the next step — solicitation of proposals.

“Here’s my point: We have to do something,” an animated Carter told the panel. “My question is, how do we get people off dead center?”

William Daniel, chief administrative officer for East Baton Rouge Parish Mayor-President Kip Holden, said the mayor prefers that such projects undergo review by area officials.

“He thought there should be meetings,” Daniel said. “They were never held.”

He said the key topic for the city-parish is solutions for traffic entering Baton Rouge on the I-10 bridge.

“It does not address the major issue in Baton Rouge,” Daniel said of BUMP.

State Rep. Franklin Foil, R-Baton Rouge, an early backer of the effort, said the project would trim traffic on I-10 and could be totally financed by AECOM.

“I am disappointed that they rejected the proposal as opposed to deferring it and allowing a new administration to look at it,” Foil said after the vote.

Despite the vote, LeBas said BUMP is not dead and the concept will continue to be studied by DOTD.

Follow Will Sentell on Twitter, @WillSentell. For more coverage of Louisiana government and politics, follow our Politics blog at http://blogs.theadvocate.com/politicsblog/.