Maryland Lt. Gov. Anthony Brown met with federal transportation officials Monday in hopes of securing funding for the proposed Purple and Red light rail lines.

Brown outlined to U.S. Department of Transportation officials the state's new transportation funding bill -- which includes a new wholesale tax on gasoline -- and a new process for giving private companies more control over public projects that he said should help convince federal transportation officials that Maryland will be able to pony up almost half the projects' cost.

"As a result of these conversations and the hard work we've done ... I'm very optimistic that we'll be able to offer the Purple Line and also the Red Line on or ahead of schedule," Brown said.

The proposed $2.1 billion, 16-mile Purple Line would run from New Carrollton in Prince George's County to Bethesda in Montgomery County. The Red Line would run east to west in Baltimore and cost almost $2.6 billion to construct.

The Maryland Transit Authority last week announced it would explore using a public-private partnership to construct the Purple or Red lines that Brown discussed Monday with Deputy Secretary of Transportation John Porcari -- who used to head Maryland's Transportation Department.

Such partnerships usually involve private business undertaking much of the cost for projects such as highway or light rail construction and being repaid through fees on users of the finished product, such as rail fares. That can mean higher costs for drivers, as private companies typically charge higher tolls than states.

Maryland's point man for rail, Henry Kay, said the thinking is that a public-private partnership would shift how much federal funding one of the lines would need and when it would be needed. That way if the federal government helps fund both lines, the burden would be less.

But there's no guarantee both will get funding. Metropolitan Washington Council of Governments Director of Transportation Ron Kirby said the Federal Transit Administration receives bids from all over the country, and it's a complicated and highly competitive process.

The Federal Transit Administration's fiscal 2014 project ratings ranked the Red Line overall as medium-high and the Purple Line as medium. They ranked Maryland's financial commitment to both as medium. Both projects were lucky, though, to make it onto the rankings list -- a streetcar planned for Northern Virginia was left off.

But Brown is confident the federal government will come through with funding.

"Look, these are challenging times, with sequestration and pressures on the federal budget, but to the extent that projects will be funded, the Purple Line is a very competitive project," he said.