DENVER, Colo. -- If you think car registration fees in Colorado are already high, hold onto your wallet.

Gov. Bill Ritter's 32-member blue-ribbon panel is recommending a $100 average increase in vehicle registration fees as part of its $1.5 billion plan to pay for much-needed transportation infrastructure maintenance and improvements.

The road funding proposals include:

• Increase vehicle registration fees by $100 on average.
• Raise the gas tax by 13 cents a gallon.
• Add a visitor fee on hotel rooms and car rentals of $6 a day.
• Increase the state sales tax by 0.35 percent.
• Increase the severance tax by 1.7 percent.

Cary Kennedy, state treasurer and co-chair of the panel, said since TABOR went into effect, the fuel tax hasn't kept pace with transportation safety needs.

"We have an obligation to make sure that the traveling public is safe when they're on our state's highways," said Kennedy.

But critics said the panel is just the governor's way of trying to legitimize a tax increase.

State Sen. Shawn Mitchell, (R) Broomfield, said that voters don't need to be taxed more, especially after Referendum C, which generated an estimated $6 billion.

"And it's still not enough," said Mitchell. "Well, I don't think we need to raise more taxes, I think we need to spend money more wisely."

The panel will present its final recommendations to the governor later this month.