The sinkhole on I-270 from the Muddy Branch Road overpass. @mymcmedia pic.twitter.com/p2K8FZl1Cx

Construction crews are waiting on a delivery before beginning repairs on a damaged drainage pipe that formed a sinkhole on Interstate 270 in the Gaithersburg area. Lane closures have created a bottleneck that officials say could last for weeks.

The 20-by-30-foot sinkhole opened June 15 in the far-right lane of southbound I-270 just north of the Interstate 370 interchange. Maryland State Highway Administration officials said it formed when a corrugated metal drainage pipe burst beneath the road.

Repairing the hole has required crews to cut out thick brush on the highway’s shoulder to make a suitable work site. State transportation officials said it took time to find the damaged pipe because several pipes are located in the area.

Two lanes were shut down on the highway, creating lengthy traffic backups in a section of highway that averages about 190,000 vehicles daily. The highway administration has been working with jurisdictions to inform motorists about emergency roadwork and suggest alternative routes.

Montgomery County transportation officials adjusted the traffic signal timing at Frederick Road, which is Maryland State Road 355 and runs parallel to I-270, to accommodate more cars.

“With schools out and our partners at Montgomery County Department of Transportation adjusting the signal timing on MD-355, this has helped reduce construction-related congestion,” said highway administration spokesman Charlie Gischlar.

Sinkhole on I-270 expected to take days to repair

State highway officials have activated overhead messages to alert drivers about lane closures in Frederick County and elsewhere to give them time to consider an alternative route before they reach the traffic slowdown, Gischlar said.

This 25 foot wide sinkhole that opened up today in the Southbound lanes of I-270 just before 370 is expected to keep at least two lanes of traffic shutdown for a week! Expect heavy delays on your morning commute from anywhere north of Gaithersburg. @nbcwashington @First4Traffic pic.twitter.com/qQorRo5M7G

Over the past week, workers have set up a concrete barrier to protect the construction site from vehicles, replacing plastic cones and barrels that initially were used. Crews have excavated the area, assessed the hole using video equipment and have found a matching section of the 30-inch pipe in another part of the region, which has assisted in being able to order replacement parts.

Crews hope to have the new section of pipe at the site within days, Gischlar said. Workers will then connect the new pipe to the existing pipe and backfill the area with stone and soil.

“The estimated time is up to a few weeks to reopen lanes,” Gischlar said. “Should we progress faster, then we can open the lanes sooner.”

A sinkhole is causing backups on I-270 in Gaithersburg area near I-370

Ride On buses continue to detour Routes 70, 71, 73, 78, 79 and 100 because of the lane closures. Transit officials had said the detours could last two weeks.

Officials with the Metropolitan Area Transportation Operations Coordination program warned again Tuesday that motorists should continue to expect to delays, particularly during the morning rush.

“Plan ahead, use alternate routes, and consider transit options,” the group tweeted.

State highway officials said they will keep drivers informed via Twitter and Facebook. Real-time travel conditions on Interstate 270 can be found at chart.maryland.gov.

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