A woman who was "heavily intoxicated" was hit by a vehicle as she tried to cross a roadway on Tucson's northwest side, authorities said.

Deputies with the Pima County Sheriff's Department were dispatched to West Ruthrauff Road and Calle Reina shortly after 7 p.m. for a report of a pedestrian struck by a vehicle, said Deputy Tom Peine, a department spokesman.

Deputies found a woman, in her early 50s, who had been hit by a Nissan Pathfinder, said Peine.

The woman was taken by Northwest Fire District paramedics to University of Arizona Medical Center with critical injuries.

A 35-year-old man was driving the vehicle, and his wife was a passenger, Peine said.

Traffic investigators determined that the woman "was heavily intoxicated and attempted to cross the roadway from south to north," Peine said.

The woman was not in a crosswalk, and the area does not have street lights, said Peine.

The vehicle was traveling west on Ruthrauff "at or below the posted speed limit," said Peine. The vehicle's driver said he tried to avoid the woman, but she walked toward the vehicle and he struck her, Peine said.  

No citations were issued, and the investigation is continuing, Peine said.