TMZ has learned 44-year-old Pasdar was arrested at 2:59 AM after cops clocked him going more than 90 mph on the 405 Freeway in L.A. We're told cops also noticed Pasdar was "failing to maintain his lane."
According to the police report, when cops approached Pasdar's ride, they detected the odor of alcohol -- and decided to give him a field sobriety test. Pasdar was eventually placed under arrest for suspicion of DUI.
Pasdar -- who is married to Dixie Chicks singer Natalie Maines -- was taken to a nearby jail, where he was booked and placed behind bars. He's listed at 5'10" and 175 lbs.
His bail was set at $15,000 -- we're told the bail amount was so high because the actor refused to take a breathalyzer.