A 49-year-old Janesville man is facing charges of Homicide by the Intoxicated Use of a Motor Vehicle after a weekend traffic crash.  The Rock County Sheriff’s Office responded to a two-vehicle head-on collision on South County Road D, just south of Hanover Road, a little before 6:00 Sunday.  Authorities say the initial investigation indicates Mark D. McCoy was traveling north and crossed the center line into the path of a car driven by a 54-year-old Janesville woman.  The woman was pronounced dead at the scene.  McCoy was treated and released at a local hospital for leg, arm and chest injuries.  South County Highway D was closed for about four-hours for the investigation.  McCoy is expected to be in Rock County Court at 3:00 p.m. Monday to face charges, which also include having Open Intoxicants in a Motor Vehicle.