The man arrested in Friday's crash that seriously injured professional cyclist Michael Torckler is suspected of being intoxicated when the accident occurred.
Arthur Ben Yu of Rohnert Park was booked into Sonoma County jail on suspicion of driving under the influence of alcohol, hit-and-run driving, stealing a vehicle and driving on a suspended license.
Yu, 36, was identified by a passenger who had been riding with him when the crash occurred on Pine Flat Road northeast of Healdburg, CHP Officer Jon Sloat said Sunday.
The passenger's statement led investigators to conclude Yu had been drinking, Sloat said.
Torckler, a New Zealander who had recently joined the Santa Rosa-based Bissell Pro Cycling team, was riding down the remote, hilly road Friday when he collided with a car driving uphill.
Torckler improved to "fair" condition Sunday, said Memorial Hospital spokeswoman Katy Hillenmeyer. Bissell team manager Glen Mitchell said Torckler on Sunday "was just starting to talk a little bit."
Torckler could acknowledge people, including his parents who had arrived from New Zealand, Mitchell said.
Mitchell expressed gratitude that the passenger decided to stay behind and contact emergency dispatchers about the crash.
"It could have definitely turned out a lot worse if that was not the case," he said.
Yu, who was arrested Saturday afternoon at his home in Rohnert Park, was accused of taking his father's car without permission, Sloat said.
Sloat said Yu has "an extensive criminal history" but he could not release details.