Phelps was clocked by radar at around 1:40 a.m. traveling 84 mph in a 45 mph zone, police said. The 18-time Olympic gold medalist was booked and released.
Police said Phelps was "unable to perform satisfactorily a series of standard field sobriety tests," adding that the Baltimore native was cooperative "throughout the process."
Representatives for Phelps could not be immediately reached for comment.
Image: Michael Phelps
Photograph: Chris Hyde/Getty Images
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