The proposed gas tax is expected to divide Maryland lawmakers.
Senate President Thomas V. Mike Miller is questioning whether lawmakers in Maryland will have the appetite for a gas tax increase, especially after they wrestle with taxes under consideration to balance the budget.
Miller says it might be better to hold a special session later this year to take up new revenues for transportation to give gas prices a chance to drop.
Changes to Gov. Martin O'Malley's budget plan approved by the Senate last week would raise income taxes to balance the state's books this year and cut an ongoing budget deficit in half in future years.
O'Malley is scheduled to testify tomorrow in favor of his proposal to phase in a 6 percent sales tax on gasoline by 2 percent a year for three years.