Because the department cannot afford to redirect revenue from one project to another, Transportation Department director Pete Rahn said funding sources are limited to user fees and tolls.
Among the funding possibilities discussed were a sales tax, fuel tax, and toll roads, all of which must be approved by a statewide vote of 51 percent.
Rahn said polls show none of these funding methods would meet 51 percent approval, but sales tax is the most popular option.
"Overall, I think a sales tax is a pretty desirable revenue stream because it grows as fast as inflation," he said.
Sen. David Pearce, R-Warrensburg, said the matching system, in which state funds are matched with local funds on construction projects, should be increasingly employed.
"If communities are willing to do some local match, then they might get ownership of some state highways that go through a town or something like that, so they have more authority to do things," he said.
Rahn said even if more counties agree to match state funds, the department still wouldn't have enough money to fund all construction projects.
"If another region of the state came to us today and said, 'We'll match fifty-fifty this project, you put in $50 million, we'll put in $50 million,'" he said, "I have to tell you we'd have to turn it down today because we don't have $50 million to match that kind of proposal."
The Transportation Department director also said many counties do not have the funds available to match state funds and that requiring a match would keep poor areas poor.
Rahn said discussions on how to fund the Transportation Department will span this year, but he hopes that a plan of action is determined before the transportation system begins to corrode.
"My hope is that in November 2010, we would know what Missouri wants, how much it costs, and that we would have a proposal."
Sen. Bill Stouffer, R-Napton, said it would be up to Missourians to decide how to fund the state's transportation system.
"There's no best way [of funding], it's whatever gets 51 percent," he said.
Susan Stauder, Vice President of the St. Louis Regional Chamber Growth Association, was scheduled to speak at the seminar, but did not come due to a change in schedule.
Stauder said in a phone interview that Missourians should focus on the state's transportation needs, not what is the best option for funding it.