The cost of building the Purple Line light rail in Prince George's and Montgomery counties has increased to $2.15 billion, according to the Maryland Department of Transportation.

The $227 million increase from $1.93 billion is the second price jump the project has seen in the last two years. In May 2011, the price of the 16-mile line between New Carrollton and Bethesda rose from the original estimate of $1.5 billion.

Maryland is now looking for $583 million more than anticipated to pay for the project and Baltimore's proposed Red Line light-rail project -- the price of which also rose, from $2.22 billion to $2.58 billion.

The state currently has none of the $4.7 billion it needs to build the two light-rail lines, nor does it have any of the $545 million it would need to build the Corridor Cities Transitway bus rapid transit system planned along Montgomery County's Interstate 270 corridor.

The Maryland Transit Administration had been hoping to pay for half of the Purple and Red lines with federal dollars obtained through the Federal Transit Administration's New Starts program.

However, the FTA recently indicated that New Starts funding will be capped at $900 million per project and $100 million annually, according to Jonathan Martin, an analyst with the Maryland Department of Legislative Services. That would pay for 40.6 percent of the Red Line and 46.8 percent of the Purple Line -- if the projects are approved -- leaving $271 million more than expected to be paid out of the state's dwindling transportation trust fund.

To qualify for the federal funds, the state needs to demonstrate where its portion of the money to build the projects would come from by the summer. Though state officials are considering a range of financing options -- from public-private partnerships to various types of loans -- all of them would require new revenue.

If state lawmakers do not pass new transportation revenues within the next year, the Purple and Red lines and the CCT would not receive federal funding, Martin said.

That could mean the projects get built in phases, rather than all at once, and delay their completion, said Jack Cahalan, spokesman for the Maryland Department of Transportation. Current plans project the Purple Line to be finished in 2020.

But state lawmakers say there is little support for a sales tax or gasoline tax increase that would help fund the projects, and multiple bills proposed over the last two years to increase transportation funds have failed.

Even if every delegate from Baltimore, Prince George's County and Montgomery County -- the three jurisdictions that would directly benefit -- voted for an increase in the gas tax, that would total only 65 of the necessary 71 votes in the House of Delegates, said House Majority Leader Kumar Barve, D-Montgomery County. "It's a heavy lift, let's just put it that way."