A new traffic pattern on the Beltway near the I-270 Spur in Montgomery County caused an unusual backup and left some drivers scratching their heads on Monday.

WASHINGTON — A new traffic pattern on the Capital Beltway led to abnormal delays in Bethesda, Maryland, leaving some commuters scratching their heads Monday morning.

Drivers on the Outer Loop encountered a newly striped portion of the Outer Loop between the “Big Curve” above the Interstate 270 Spur and River Road.

Last month, Maryland Gov. Larry Hogan outlined the Maryland State Highway Administration’s plans to implement “quick improvements” for congestion relief on I-270.

The southbound lanes that connect the I-270 Spur with the Outer Loop were re-striped late last week to allow all three lanes from the spur to continue through toward Virginia. To make room for the additional through lane from I-270, the highway administration dropped a right lane on the Outer Loop south of the Bradley Boulevard overpass.

The change led to a period of congestion during the first rush hour of the workweek. Drivers cited an unusual backup near Rockville Pike and Old Georgetown Road.

A spokesperson for the highway administration said that with any new traffic pattern, there will be an adjustment period as drivers slow to observe the changes.

The merge is in its final configuration, but the lane markings are temporary. Overnight milling and resurfacing is scheduled to take place one lane at a time throughout the fall months.

Hogan also announced an ambitious plan late last month to construct express lanes around the entire Beltway in Maryland. The state’s future plans to improve traffic on I-270 include extending carpool lanes, adding a third local lane and constructing a new interchange for Watkins Mill Road in Gaithersburg.