A cyclist who was badly injured Wednesday evening in an east Santa Rosa collision with a vehicle has been identified as Ian Thomas Borden, 25, of Santa Rosa.

Borden remained hospitalized in critical condition Thursday, less than 24 hours after he was struck by a vehicle while crossing Highway 12 at Boas Drive, just west of Calistoga Road, police said.

Authorities said the driver in the 5:09 p.m. crash, Citrus Heights resident Oleksandr Kachan, 50, was traveling eastbound when he came upon Borden too late to stop and avert a collision. Police said Borden was crossing the four-lane highway from north to south without a crosswalk or a signal, and Kachan just didn’t see him in time.

The incident snarled eastbound traffic Wednesday for about three hours because of closed lanes.

Anyone who witnessed the crash is asked to call police investigators at 707-543-3636.

You can reach Staff Writer Mary Callahan at 707-521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.