A Novato woman severely injured in a head-on crash Tuesday in Sonoma County was expected to survive, the CHP reported Wednesday.

The young man suspected of causing the Stony Point Road accident remained hospitalized at Santa Rosa Memorial Hospital in fair condition.

Ben Rhoades, 19, of Sebastopol was arrested after the crash on suspicion his driving was impaired due to drugs, said the CHP.

Officers found a hypodermic needle in the cab of the truck he was driving and said he showed signs of drug impairment, said CHP Officer Jon Sloat.

The Stony Point Road crash occurred at about 8:30 a.m.

Rhoades' Ford F250 truck crossed the double yellow lines and smashed into the Ford SUV driven by Vicki Siefer, 46, of Novato.

Both were taken to Santa Rosa Memorial Hospital. Siefer was later flown to Stanford Hospital with what the CHP said were life-threatening injuries.

Sloat said the woman's condition had improved Wednesday.