Shortly after 2 a.m., California Highway Patrol officers responded to reports of a driver heading westbound down the eastbound 118 Freeway just past Reseda Boulevard.
The driver was apparently moving slowly on the HOV lane for about 15 minutes.
Officers caught up with the driver in Chatsworth near Topanga Canyon.
The driver was arrested. No one was injured.
The driver's identity and possible charges were not immediately known.
City News Service contributed to this report.