ANNAPOLIS — The state transportation secretary, Darrell Mobley, got an earful from Republican delegates on the Appropriations Committee on Friday.

The Republicans wanted to know how much transportation funding had really been diverted to other programs and questioned why more transportation money was spent on mass transit than on public roads this year.

“We were told that all of the money from the general fund has been paid back, but there’s about a billion dollars from the highway user fund that has not been returned,” said Delegate Nancy Stocksdale, R-Carroll.

Stocksdale was referring to the $1.1 billion of highway user revenues that have been diverted from the transportation trust fund to the general fund since 2003.

Legislative analyst Jonathan Martin explained that highway user revenues are not technically part of the transportation trust fund and that because they are a legally distinct entity, the O’Malley administration is correct in saying that it paid off all its debts to the transportation trust fund.

Delegate Tony McConkey, R-Anne Arundel, called this a deceptive argument based on a “legal fiction,” and urged his fellow legislators to create “a lockbox” to prevent the state from using transportation funds for alternate purposes.

Mobley, the acting secretary of transportation for seven months, agreed that the department funds needed to be shielded from redistribution. “I know that there are sometimes fiscal emergencies, but there needs to be some kind of lockbox,” said Mobley, who added that his agency had woefully inadequate funds.

Mobley said that the transit system has needed renovation “for decades” and that Maryland’s roads are the most congested in the United States. “Without a major revenue increase, our roads will be even more congested,” he said.

That was perhaps the only point that Mobley and Republican delegates agreed on. During the rest of the hearing on the department’s budget, they challenged the secretary to justify the choice to devote 40 percent of his agency’s proposed 2014 budget to public transit and 13 percent to State Highway Administration.

Republican delegates also suggested that Baltimore City received a disproportionate share of transportation funds.

Delegate Wendell Beitzel, R-Garrett, complained about the “diminishing amount of highway spending” and argued that “money collected from cars on the highway” should be spent on roads rather than mass transit.

Mobley said that this claim of imbalance was unwarranted and based on “misconceptions,” since his agency had spent the bulk of its resources on roads for most of its history.

“While highway spending is on the decline, I would like to point out that ... it is only very recently that spending has shifted to transit,” he said, explaining that he needed to remedy years of neglect of Baltimore City’s public transit system, which still needs improvement.

Committee Republicans seemed unconvinced by that argument.

On Monday, the state tea party’s original organizer, Americans For Prosperity-Maryland, complained that 45 percent of this year’s transportation expenditures went toward mass transit and “49 percent of transportation revenue came from drivers but only 30 percent was spent on road construction and repair.”

Nick Loffer, grassroots director of Americans For Prosperity, argued that any revenue raised by a gas tax “will go toward mass transit, not roads and bridges.”

But Democratic Delegate Theodore Sophocleus, Anne Arundel, countered such arguments, saying that the state needed to raise additional revenue for mass transit to spur economic growth and job creation.

Sophocleus argued that new trains, subway stations and bus stops would result in additional state revenue from income taxes and corporate taxes, since an efficient transit system would make it easier for citizens to go shopping and go to work.

“Shouldn’t the revenue produced by people getting jobs and generating income override the expense of getting them to the job?” he said, adding that restaurants near transit stops in his district were packed with customers largely because of their location. “That economic impact should be taken into account when we measure the cost of transit.”