Security checkpoints at the two busiest concourses at BWI Thurgood Marshall Airport will be temporarily closed at separate times this week to allow for construction, officials said.
The two checkpoints serve airline gates for Southwest Airlines and its subsidiary, AirTran Airways, which account for more than 70 percent of the airport's passenger traffic.
The Concourse B security checkpoint is scheduled to be closed on Monday from 1 p.m. until Tuesday at 4 a.m. The checkpoint at Concourse A will remain open.
The Concourse A checkpoint is scheduled to be closed on Tuesday, from 1 p.m. until Wednesday at 4 a.m. The checkpoint for Concourse B will be open.
Airport officials recommend that Southwest and AirTran passengers use the new nine-lane security checkpoint between Concourses B and C, which opened last month. That checkpoint serves all airline gates on Concourses A, B and C.