This rendering shows public gathering space before the security checkpoint entrance at Reagan National Airport. This security checkpoint will be built above that Arrivals roadway and connect to the National Hall. (N/A/MWAA - Project Journey)

Work begins next week on a $1 billion revitalization project at Reagan National Airport that officials say will deliver a new concourse for short-hop flights and new security screening areas in 2021. But it will be a painful process getting there — with lane closures and traffic disruptions around the area as construction starts.

Construction activity kicks off Monday, closing travel lanes overnight in the Arrivals area of terminals B and C. By spring, the stretch of the lower-level roadway that provides access to the airport will be a round-the-clock work zone with more widespread lane shutdowns, the kind that will probably create traffic backups.

The work will not affect the upper-level access road used for departure drop-offs.

If you travel frequently, or at all, from National, now is the time to start paying attention to what’s coming.

“In the first year of construction, some of the impacts on the roadways will be such that considering alternates is going to be strongly advised,” said Rob Yingling, a spokesman with the Metropolitan Washington Airports Authority, which operates National.

A rendering of the new concourse with 14 gates connected to regional aircraft at Reagan National Airport. (N/A/MWAA - Project Journey)

The authority says that despite traffic-control measures, there’s no way around the construction. Drivers should prepare for backups and heavier traffic near the terminals. Motorists also should anticipate changes to traffic patterns. Ride-hailing services such as Uber and Lyft could be diverted to pick up customers on the departures level instead of arrivals.

Metro might be your best bet for avoiding the construction zone. But two major maintenance projects will affect the National Airport Metro station later this year.

Airport police will manage traffic flow, officials say, and they anticipate more significant backups when heavy construction takes place this spring and into the summer, as well as during peak travel periods around the holidays. But they say they don’t foresee chaotic scenes like those experienced at other big-city airports undergoing major construction.

In New York, for example, construction activity related to a $5.1 billion project at LaGuardia Airport has led to massive traffic tie-ups on access roads, including cases in which fliers have been forced to drag their bags along the side of the road just to get to the airport.

“Compared to LaGuardia, the work that we are doing here is less invasive, less extensive and it is not expected to have the same level of impact,” Yingling said.

The construction at National won’t take any airline gates out of service, remove roadways or demolish parking garages “on the scale of what’s happening at places like LaGuardia,” he said. “It’s really about improving the airport experience, given the explosive growth in enplanement that has taken place at Reagan National, while not expanding the operational capacity of the airport.”

Nearly 24 million passengers traveled through National in 2016, the latest year for which data is available, making it the second-busiest airport in the region, after Baltimore-Washington International Marshall Airport. It was National’s sixth straight year of record-high passenger traffic.

And that’s a reason, officials say, to embark on this ambitious “Project Journey” — which also is the first major construction rehabilitation at the airport in two decades.

Frequent fliers who choose National for the easy access say they appreciate the improvements but add that they hope the airport keeps the impact on travelers to a minimum.

“We will probably play it by ear and see just how bad it gets,” said Sheldon Gilbert, an Arlington resident who travels out of National almost weekly on business. “It is hard to imagine those of us who are frequent users of Reagan making a switch to another airport. There might be frustration with the congestion and we might have to budget in more time to get in and out of the airport. But it still is going to be probably less time than driving to BWI.”

In the coming weeks, some travel lanes will close to give workers — and equipment — room to begin laying the groundwork for heavy construction, expected as early as the spring.

A new concourse will replace the infamous Gate 35X, a chokepoint where fliers are required to board buses to get to their planes. The concourse will be next to terminals B and C on the airport’s northern end. The project also will bring changes to National Hall, the main glass-enclosed walkway on the concourse level. Security screening will be moved upstairs to the airport’s arrival level, closing the hall off to the general public. Officials say travelers will be able to move through security faster in the new setting, which will have 28 screening lanes, up from 20.

The construction of two buildings that will house the new security screening areas will generate the most significant impacts on vehicular traffic; they will be built over some of the traffic lanes for arrivals.

That lower-level roadway has eight lanes divided by a median where passengers wait for their rides. The four lanes closest to the airport entrance are used by commercial vehicles such as taxis and shuttles. The other four lanes, closest to the Metro tracks, are used by general traffic.

Work will be done at night this week to create three slip ramps in the pedestrian median. This will allow authorities to move traffic through work zones during later phases of construction, by shifting traffic from the commercial lanes to the general traffic lanes and vice versa. Some sections of the roadway will be widened in early March, as part of a strategy to expand the road capacity during construction.

Drivers entering the airport from the George Washington Memorial Parkway or Route 1 will encounter the signs of construction as they get closer to the terminals. The actual construction will be on the airport road used to pick up arriving travelers, and affecting the activity at the curbs of terminals B and C.

By mid- to late March, cranes will be on-site to begin excavation and building the underground pilings for the 100 columns that will support the security screening buildings just outside terminals B and C. That work will last about a month and require round-the-clock closures of two lanes.

As construction begins, most of it will be done overnight, from midnight to 9 a.m., which means crews will have to pack up their equipment after each shift to allow for traffic flow — not the most efficient way to work, but the only way to ensure smooth travel during the airport’s busiest hours.

“I have seen the airport recommend folks take Metro,” said Gilbert, who works at a nonprofit group based in Arlington and hails a ride to and from the airport. “It is just so painful using Metro these days. It is kind of a poor alternative given the track record of Metro.”

Airport officials are recommending travelers leave the airport via Metro to avoid navigating through the construction zone in the arrivals pickup areas. They also say fliers can meet their rides in the airport’s parking garage to avoid the work zone entirely. As construction progresses, the airport may consider offering free parking for up to an hour for people picking up travelers and sending ride-hailing services to the departures area.

“It is great that they are expanding the airport. But they ought to be very sensitive to what experience they are providing for people who are trying to get in and out of the airport and whether they are maintaining the principal benefit of Reagan, which has always been that it is convenient to get in and out,” Gilbert said.