Construction on a new interchange at Interstate 270 and Watkins Mill Road will begin this month, offering better access to the Gaithersburg area and alleviating traffic congestion on surrounding local roads, Maryland officials said Tuesday.

Work on the 1.25-mile project north of Montgomery Village Avenue (Route 124) is scheduled to begin any day and is expected to be completed by summer 2020, officials said.

Lane closures in the heavily congested commuting corridor will be limited to outside the morning and evening rush, with most during the midday or overnight hours, highway officials said.

“Anyone who travels through this part of Montgomery County knows how bad congestion can be,” Maryland Gov. Larry Hogan (R) said at a groundbreaking ceremony where Watkins Mill Road now dead-ends on the highway’s east side.

State and local officials said that a new interchange will relieve side roads that are jammed much of the day with Gaithersburg-area traffic trying to enter and leave I-270. The highway has one of the state’s largest jobs corridors and is a major commuting route between Maryland, the District and Northern Virginia.

Building an interchange north of the one at Montgomery Village Avenue/Quince Orchard Road (Route 124) has been a top priority for county officials for more than a decade, particularly after the Gaithersburg area boomed from farmland into office parks, shopping centers and subdivisions. East-west connections, such as a completed Watkins Mill Road spanning the highway, also have lagged behind in a suburban county where the road network long focused on north-south routes into and out of downtown Washington.

The interchange project, which will cost $97.7 million, will coincide with $100 million of additional construction aimed at reducing congestion and improving safety on I-270, officials said. That work, which is expected to begin in the fall, will include new ramp metering, stretches of new lanes and overhead signs with more details about slowdowns ahead.

Montgomery County Executive Isiah Leggett (D) said that a new interchange will help motorists such as his sister, a doctor who commutes from Laurel to Gaithersburg for her job with Kaiser Permanente.

“Whether simply for convenience or for businesses . . . this is helpful,” Leggett said.