An agreement between the state of Maryland and federal transportation officials has cleared the way for the $5.6-billion Purple Line to receive the entire amount of its previously approved Federal Transit Administration funding grant, allowing construction of the long-delayed project to begin as early as September.

An Aug.  21 statement from the U.S. Dept. of Transportation says the 16-mile public-private light-rail project across Washington, D.C.'s northern suburbs "met all of the statutory and readiness requirements" for FTA to sign the $900-million federal grant agreement.

Originally recommended for allocation in fiscal 2015, the FTA grant had been on hold since August 2016, when a federal judge halted the Purple Line just days before its Fluor-led consortium, Purple Line Transit Partners, was set to begin construction.

While the judge was weighing challenges to the line's ridership projections, the project's future also was clouded by the Trump administration's March announcement of proposed cuts to transit funding programs. As delays and costs began to mount, the Maryland Transit Administration in late May ordered pre-construction work scaled back.

Since then, however, the Purple Line has prevailed in court, with the dismissal of environmental-related lawsuits and a July 19 federal appeals court's emergency stay that allows construction to begin while remaining lawsuits are resolved.

In a statement, the U.S. Dept. of Transportation said the Purple Line "is an excellent example of leveraging a transit project through a public-private partnership," noting that it is expected to be "a model for other infrastructure projects across the country."