The driver intentionally nudged a light-weight plastic orange construction barrel a couple of feet out of the way so the vehicle could reach a checkpoint, and did not drive through police tape, the official said.
There was no damage to the vehicle, which then proceeded to a second checkpoint. The entire incident lasted less than two minutes, the official estimated.
The vehicle did not drive over the suspicious package, although it was in the vicinity, the official said. The package later was found to be a book wrapped in a green shirt.
The Post reported Secret Service officers on duty suspected the agents were drunk, but a supervisor let the agents go home. That issue is under review by the Inspector General of the Department of Homeland Security.
A Secret Service official said the two employees have been reassigned to non-supervisory, non-operational assignments. A spokeswoman declined to provide the agents' names.
The agency was criticized as being too insular by an independent panel appointed in the wake of an intrusion last year, when a man with a knife scaled the White House fence and ran inside the mansion.
That incident prompted former Director Julia Pierson to resign. She had been director for two years, named to the top job after agents were accused of hiring prostitutes during a 2012 trip to Colombia.