A woman who crashed her pickup into a pole on state Highway 12 southeast of Santa Rosa this morning was arrested on suspicion of being under the influence of methadone, a California Highway Patrol spokesman said. Jean Wonnacott, 46, of Kenwood, is believed to have fallen asleep and drifted off the road because she was impaired, CHP Officer Jonathan Sloat said. Wonnacott was driving a 1988 Nissan pickup east on Highway 12 near Randolph Avenue in Kenwood at 55 mph when she struck a utility pole around 6:30 a.m., Sloat said. The impact sheared the pole and knocked electrical and telephone wires onto both lanes of the roadway, Sloat said. An officer at the scene said Wonnacott’s seatbelt likely saved her life, Sloat said. She suffered moderate injuries and was taken to Santa Rosa Memorial Hospital. She was arrested there and released to the hospital for treatment, Sloat said. The highway was closed and traffic was rerouted until 9:35 a.m., Sloat said.