Lamar Odom was arrested for "driving under the influence of alcohol and/or drugs" in a white Mercedes at 3:54am on Friday on the 101 freeway in the San Fernando Valley.

California Highway Patrol pulled the troubled NBA star over after noticing that he was driving in a "serpentine manner" and going only about 50 miles per hour. Lamar drove past 3 exits before he finally pulled over, and law enforcement sources tell TMZ he showed "obvious signs of intoxication."

Lamar failed several field sobriety tests, and he was then taken to a nearby station, where he was booked and held on $15,000 bail. The website also reports that when Lamar was booked, he refused all chemical tests.

Lamar has been in the news lately for his marital drama with Khloe Kardashian and his alleged drug addiction, but just two days ago we snapped him driving his Mercedes SUV to a Taco Bell drive-through, and he seemed to be in good spirits. After grabbing some grub, Lamar returned home to the Tarzana pad he shares with Khloe, so we were under the impression that things were getting better. Guess not!

Lamar was released from custody at 8:33am this morning and he is set to appear at Van Nuys Municipal court on September 27 to face charges. He's still at the police station though -- stay tuned for pix and video of him leaving!