Detectives are investigating the possibility that the suspect who was driving the 2007 Honda Civic may have been racing another vehicle southbound on the Alaskan Way Viaduct when it struck the 2000 Mitsubishi, also travelling southbound in the center lane.  The collision, detailed in the previous post, caused the shutdown of the roadway for several hours in the 2300 block of Highway 99 southbound.  Detectives from the Traffic Collision Investigation Squad (TCIS) responded, as did the Seattle Fire Department.  The driver of the Honda was evaluated for signs of impairment.  TCIS detectives completed their investigation at the scene and the roadway is now back open.  Detectives continue to actively investigate this collision.