Gretchen Rossi can't drive 55 (or even twice that), as shown in brand new court papers, exclusively obtained by RadarOnline.com, detailing the The Real Housewives of Orange County's speeding violation last summer, when Nevada authorities say she was going -- drum roll, please -- at least 116 mph!

EXCLUSIVE LEGAL DOC: Gretchen Rossi Speeding Ticket – 116 mph!

Rossi, 31, received the ticket as she was venturing through Las Vegas during the annual Gumball Rally; police said the blond bombshell was driving between 41-50 mph more than the posted speed limit of 75 mph.

Records indicate Rossi paid a steep fine -- $600 -- for her allegedly lead-footed ways.