If the weather holds, Baltimore-Washington International Thurgood Marshall Airport this weekend will close its two busiest runways for about 54 hours, relying on a shorter, little-used one as it repaves a critical intersection.

Airport officials said passengers and travelers should expect flight delays throughout the weekend as it completes the maintenance project — the first such closing in more than two decades.

A spokesperson for Southwest Airlines said it is advising customers to expect delays on Sunday.

BWI has four runways: two for commercial traffic, one for general aviation and a fourth that is seldom used, said spokesperson Jonathan Dean. The two main runways are 10,500 and 9,500 feet long, while the little-used runway known as 4-22 is only 6,000 feet long.

During the weekend closures, BWI will utilize runway 4-22 for most commercial operations. It has approach and departure paths that overfly areas to the northeast of Aviation Boulevard and southwest of MD 100 (Arundel Mills and Severn areas).

Officials said residents of those areas may notice a shift in aircraft activity because of the runway closures.

Travelers with scheduled flights or those who plan to pick up arriving passengers should check flight status before heading to the airport.

If weather conditions prevent the work, the project will take place next weekend.