At 0700, we got a call for a car through the guardrail and down in an embankment. Location was on a bridge. Responded direct as IC. Upon arrival, driver was out refusing treatment, car was off the road, no hazards. Canceled fire response.. Had two PD cruisers lights on, and the EMS medic-lights on. I had all my lights on blocking the bridge passing lane as it was icy. Everyone was standing off the roadway but stayed parked there just in case. All of the sudden I look in my rear view and see a red grand prix swing into icy passing lane to go around a dump truck. She lost control and I watched as she gained speed headed right for me. I was buckled in. I just leaned back in my seat quickly just before she hit. The force spun my car around and the opposite side then struck the bridge deck wall. My portable hit the windshield. The important thing was that I was in between crazy lady driver and all pedestrians or it would have been ugly. We were both ok although she was freaking out a bit.