Law enforcement sources tell us cops noticed Justin's white Ferrari blowing through a stop sign near his Calabasas home around 4:30 AM Wednesday morning. We're told Justin was cooperative during the stop -- but cops noticed that JB did not have a valid California driver's license, something new residents of the state are required to have within 10 days of moving to CA.

Sources say Justin was cited for running the stop sign and for driving without a valid California License. JB was ordered to get out of the driver's seat -- and his passenger was allowed to drive the car home.