Here are three truisms that I’ll invoke for this discussion: Black ice on roads appears suddenly and is really dangerous, a set of doubles can be hard to control, and a video is worth thousands of words.

This one is so graphic that parts of it, shot by a motorist on the New Jersey Turnpike, were picked up by ABC and CBS in their evening newscasts one day last week, when a snow and ice storm moved up the East Coast.

The double-trailer rig bounds over the guardrail separating the truck-and-auto lanes from the auto-only lanes. When it finally stops, we can see the truck driver opening his door and preparing to get out just as an unseen car smashes into the rear of his second trailer. That’s how chain-reaction crashes unfold.  

By the way, on black ice, all the anti-lock braking systems in the western world can't do much to control a multi-trailer combination, let alone a simple tractor-trailer.  

The motorist, who had the sense to hold his smart phone horizontally as he shot the video, later told a TV news interviewer that he was glad that the wreck ended with just “some bent metal.” He also said he went to church to give thanks that no one was hurt. Amen.