The ramp from Interstate 395 HOV lanes to the Mark Center has been delayed by up to 18 months. The Federal Highway Administration is requiring a longer environmental study than the one proposed by the Virginia Department of Transportation.

The $80 million ramp is one of several proposed transportation projects to handle the 6,400 new federal employees coming to the Mark Center because of the Base Relocation and Closure (BRAC) moves this fall.

State transportation officials said the $80 million set aside for the project would be in jeopardy if a longer study was conducted.

The shorter study “is the appropriate level of environmental documentation since the ramp will be built entirely within existing I-395 right of way, will improve air quality by making transit and carpooling more convenient for Mark Center employees and will not have substantial impacts to natural, cultural, recreational, water quality, or historic resources,” said a statement from VDOT.

Alexandria residents and the local BRAC stakeholders advisory group favored the longer study at a March public hearing. The residents said they wanted the longer study because it included air quality and noise impacts, as well as more public hearings and alternative routes.

State transportation officials estimated construction would be completed by 2014 if the shorter study was chosen.