The Federal Highway Administration is postponing a decision on the contentious CSX Virginia Avenue Tunnel project until at least Sept. 15.

The agency had already extended the review period of the project, at the request of D.C. officials.

Del. Eleanor Holmes Norton (D-D.C.), who asked for the additional time to review the case, said holding back the decision that finalizes a required federal environmental review will allow the city to do oversight of the District Department of Transportation.

The D.C. Council is scheduled to hold an oversight hearing next week to listen to residents’ concerns about the proposal and review the city’s role on the project’s permitting process.

“It is the Council’s obligation to D.C. residents to provide appropriate oversight of the project, and it is only fair that FHWA respect the time needed to accomplish this obligation,” Norton said in a release sent Tuesday.

The Federal Highway Administration in June extended the review period of the final environmental impact statement from 30 to 60 days and added a second public meeting on the project.  The proposal to rebuild the 110-year-old tunnel in Southeast Washington has been under review for years and has become one of the city’s most contentious projects.

Some residents who oppose the project say they hope the city will find a way to stop it from happening, at least until the city conducts a comprehensive rail study.

“This analysis of all rail service in the District will allow the coordinated expansion of passenger, commuter, and freight service,” said Maureen Cohen Harrington, a member of a coalition of neighbors that oppose the project.

But other neighbors and stakeholders say after years debating the project, it is time to get it done.  The aging tunnel is a major piece of the region’s rail network, and CSX Transportation wants to rebuild it to fix some structural problems and so it can accommodate double-stacked container freight trains.