Update 10:15 p.m. EDT: The man is identified as Mathew Evan Goldstein, 55. He was arrested and charged with unlawful entry.
Update 6:20 p.m. EDT: The Secret Service says the unnamed driver holds a Treasury Department pass, CBS reports. Nothing threatening was found in his car, but he is still in custody and being questioned.
Update 5:55 p.m. EDT: The incident is "over" and nearby streets have been reopened, the White House says.
Security officials locked down the White House Tuesday afternoon after a car tried to follow a motorcade carrying President Barack Obama's daughters past a checkpoint, the Secret Service told NBC.
The driver is in custody after trailing the motorcade onto Pennsylvania Avenue. The car, a Honda, is being searched.