When Gov. Martin O’Malley convinced Maryland lawmakers to raise the gas tax this year, he not only secured billions of new dollars for transportation projects. Finding a new transportation secretary also became a lot easier.

Both O’Malley (D) and former Baltimore County executive James T. Smith Jr. (D) said Wednesday that the funding package was key to Smith’s decision to take a Cabinet-level post that had been open for close to a year.

Prior to the legislature’s action, transportation officials said they were on the verge of running out of money for new road and transit projects. They now say they have another $4.4 billion to spend over the coming six years, including in the heavily congested Washington region.

“The position became much more exciting when the legislature voted to modernize our transportation infrastructure,” O’Malley said after announcing Smith’s appointment at the site of an ongoing bridge replacement project in Catonsville.

Smith, 71, a lawyer and longtime political ally of O’Malley, said that in addition to overseeing new construction, managing “pent-up demand” for projects will be one of his greatest challenges, now that there are the additional dollars to spend.

“Not that much has happened for too long a period of time,” he said. “There’s plenty of vision and plenty of studies, because that’s about all you could do.”

Earlier this month, as O’Malley signed the gas-tax increase into law, he released an initial list of $1.2 billion in new spending, including $280 million in design work on the Purple Line, the proposed rail link between Bethesda and New Carrollton. Extensive federal funding also will also be required to make that project a reality. Smith said Wednesday that it will be a priority.

The 10,000-employee department that Smith will oversee also is planning to spend an additional $100 million in design work for the Corridor Cities Transitway, a rapid bus line envisioned along Interstate 270. Expanded MARC train service on weekends and several new interchange projects around the state also have been announced.

And on Wednesday, after formally unveiling Smith as his new secretary, O’Malley announced another $90 million project: widening of a one-mile stretch of the Baltimore Beltway on what Smith called its “wicked west side.”

The cost for the new projects will largely be borne by motorists, who can expect to pay 13 to 20 cents more per gallon of gas by mid-2016, according to legislative analysts. The increase will be phased in, with the first bump of about 4 cents a gallon coming in July.

The increases will the result of a couple of upward adjustments in the gas tax. The state will start imposing a new sales tax on the commodity in addition to gradually raising the current 23.5 cent-per-gallon flat tax, which has been unchanged since 1992.

The cumulative effect will likely make Maryland one of the more expensive places to buy gas.

As of January, Maryland’s tax was the 29th highest among states, according to an analysis by the Tax Foundation, a nonpartisan research group based in Washington. Once fully phased in, the bill passed by the legislature would catapult the state into the top 10, if projections by state legislative analysts prove true.

Smith succeeds Beverley Swaim-Staley, who resigned in July. According to O’Malley aides, O’Malley considered naming Joseph C. Bryce, the governor’s former chief lobbyist, as transportation secretary. But Bryce instead left the administration to become a lobbyist.

On Wednesday, O’Malley also named Robert L. Smith as the administrator of the Maryland Transit Administration, which oversees bus and rail service.