Travis Myers, 30, of Garden City, crashed a Kawasaki motorcycle around 7:35 a.m. on Thursday.
He was not wearing a helmet. Neither was his passenger, 30-year-old Melissa Thompson of Boise. Myers has been in critical condition at St. Alphonsus Regional Medical Center in Boise since the crash. Thompson was treated and released.
The nature of Myers' injuries are unclear. Hospitals typically do not release that information.
The crash occurred in clogged traffic during peak commuting time Thursday morning. Idaho State Police reported that Myers didn't slow down as Chevy Impala driven by Lorraine Tracy, 52, of Wilder, slowed down in front of him. Instead, Myers reportedly swerved to avoid the car. But the motorcycle clipped the car's bumper.
Myers reportedly laid the bike down and it crashed on top of him. Thompson was thrown from the motorcycle.
The Impala sustained only minor damage, and its driver was not injured, according to ISP.