They're raising the roof at Charleston International Airport, and that's going to affect travelers starting in January.

As part of the $189 million overhaul of the main terminal, part of the roof will be removed over the next few months so workers can install a dome that will let sunlight stream into the central atrium area.

That, in turn, will create traffic issues outside. The four traffic lanes closest to the building will be closed at least through April because a construction crane will be obstructing the flow.

The decorative beams over the lanes will also be replaced. The outside lanes will remain open but will probably be more congested.

And that's just the start.

For much of the past year, work has gone on mostly behind the scenes. But over the next 18 months, it's going to be front and center.

"What you will see starting in January will impact the flow of passengers," said Paul Campbell, airports director for Charleston County Aviation Authority.

For example, crews will begin dismantling the front brick wall of the terminal and replacing it with glass.

Also, temporary passageways will be placed in the terminal to steer workers around construction zones. Signs will direct passenger flow.

"We plan to make it easy to navigate the terminal while it is under construction," said John Connell, deputy director for engineering and planning for the Aviation Authority.

Among the other temporary changes: The restrooms near the Concourse A checkpoint will close, but those at Concourse B and in the boarding areas will remain open. Hudson News will consolidate its news stand with the Discover Charleston Shop.

Some temporary walls have already gone up. One shields the area where a third baggage carousel will open in January. Afterward, the other two will be closed and replaced, one at a time.

As the year progresses, construction will encompass the entire terminal.

"It's going to take a little longer for people to get to the gates, so they should allow more time," Campbell said. "It will be pretty and functional when it's completed, but for a period of time it's going to appear we are a little dysfunctional."

Reach Warren L. Wise at 937-5524 or twitter.com/warrenlancewise.