The crash happened around 12:45 a.m. Saturday at the restaurant located on the 22300 block of Old Canal Road.
Officers say the truck flew off the westbound 91 Freeway off-ramp and landed right where drive-thru customers give their orders.
The driver reportedly sustained minor injuries and was transported to a hospital.
The menu board and about 50 feet of guardrail were damaged.
Authorities say they are investigating this as a possible DUI crash.
