"The driver may have intentionally struck the security barriers," Anthony Guglielmi, chief of communications for the US Secret Service, said in a tweet.
Some roads and pedestrian walkways around the park were closed, the Secret Service added, Reuters reported.
He noted that the cause and manner of the crash are under investigation.
The incident - which happened just before 22:00 (02:00 GMT) - triggered evacuations of local hotels including the Hay Adams.
AMK/PR