NPR coverage, starting with
The fastest human to ride a bicycle over open ground is named Denise Mueller-Korenek, who rode a custom bike at an average of 183.932 miles per hour – shattering a world record that had stood since 1995.
Mueller-Korenek, 45, set the record for fastest speed riding in a slipstream, teaming up with Shea Holbrook, a professional race car driver who piloted a dragster that led the cyclist across the Bonneville Salt Flats in Utah.
https://www.npr.org/2018/09/18/649221471/woman-rides-bicycle-to-183-9-mph-a-new-world-record
Such high-speed attempts are done behind a fairing to protect from wind and make the ride stable. She had to be towed to get up to 100 mph before she could pedal on her own.
And, the scariest part of the ride was slowing down. It took super coordination with the tow driver to get down to 70 mph so she could brake.
The NPR article includes a 3:25 minute video documenting the ride.