Yeah. You kinda misread that report and/or what I was talking about.
First, I clearly was talking about what would be your final option in case you were stuck in a car, in traffic preventing you from leaving the scene.
That's not what the report is talking about. It's talking about how people used to think that was one of the safest places and would a actually leave their homes (which would be safer) to go to an overpass, or would park their still mobile car and wait up to ten minutes under the overpass while the tornado came, when they could have just sped away in their cars.
That's not what I was talking about. I was talking about imminent danger when you are trapped in traffic away from adequate shelter.
The report itself echoes my statement:
http://www.srh.noaa.gov/oun/?n=safety-overpass-slide24
So just take it easy on me, OK? I was clearly answering a specific "worst case scenario" question.