DES MOINES (AP) -- Iowans could pay more at the gas pump in coming years as state officials seek more money for road construction.

The Iowa Department of Transportation released a report Tuesday that proposes raising several taxes and fees to offset an anticipated $27.7 billion shortfall in the next two decades.

"While the system is not yet broken, it is at the tipping point where the cost to recover will grow exponentially if action is not taken now," the report said.

The Legislature in 2005 asked the DOT to examine funding shortfalls prompted by flattening revenues, dramatically increasing construction costs and aging infrastructure.

DOT's report suggests raising taxes to generate at least an extra $200 million annually in road construction revenue. This would be the equivalent of about a 9-cent per gallon increase in gasoline and diesel fuel taxes.

Taxes could also be raised in other ways, ranging from increases for pickup truck registrations to boosting fees for driver's licenses, the study said. The report also suggested establishing toll roads, although it didn't specify which stretches of highway could be used.

Sixty percent of the extra money would go to state road projects, with 20 percent to cities and 20 percent to counties.

The report's findings are expected to fuel a debate during the upcoming legislative session over road financing issues.

The office of Gov.-elect Chet Culver released a statement Tuesday saying Culver will review the report but has not pledged support for the DOT's suggestions.

"Governor-elect Culver did not run on a platform that included increasing the gas tax, increasing truck and driver's license fees and toll roads," the statement read.

"These things will not be in his upcoming budget, which will focus on renewable energy, education, job creation and health care."

At the state level, critical needs exist on the interstate highway system and on the state's co-called "Commercial and Industrial Network" of major state highways, the report said. Without more money, it will be difficult to complete improvements on highways U.S. 20, U.S. 30, U.S. 34, U.S. 61, U.S. 63, U.S. 169, and many others, the DOT said.

At the county level, several deficient bridges and deteriorating conditions on the farm-to-market road system are affecting the movement of people and goods, the study said. If these needs are not addressed, more bridges will close and roads vital to the movement of agricultural products will deteriorate, affecting local and statewide economies.

Cities are facing similar issues, the report said, including deteriorating pavement, deferred and reduced maintenance, and the inability to meet the demand for new roads.

Money generated from raising state road taxes would be placed in a new account called "Transportation Investment Moves the Economy in the 21st Century (TIME 21) Fund," the DOT report proposed.

"Additional investment in Iowa's public roadway system is vital to sustain and grow our state's economy," the study said. "This new fund will target new revenue to those areas particularly important to Iowa's economy."