Maryland transportation officials say the financial plan for building a $2.2 billion Purple Line between Bethesda and New Carrollton is still fluid. However, these are some potential sources of construction money:

$750 million in state funds (from the Transportation Trust Fund, which includes revenue collected from the new gas tax, vehicle titling fees and other taxes).

$900 million in federal transit construction grants (not yet obtained).

$500 million to $900 million in private funding (the state would pay off the private sector’s construction borrowing costs over time, using annual Purple Line ticket revenue estimated at $35 million to $40 million per year).

$220 million ($110 million each) from Montgomery and Prince George’s counties

Source: Maryland Department of Transportation