On Interstate 70 in northwest Kansas, just past the exit for the town of Edson, a dozen or so skidmarks cross the pavement. Some go straight, some bend toward the median strip or curve toward the right-hand shoulder and disappear in the longer grass. Shiny, dusty, Rorschach-blot stains from various fluids fade in the sun as the traffic rolls over them. Most drivers probably don’t notice this piece of road-script that goes by in a tenth of a second like the scrawled pen markings at the beginning of an old film. The breadth of the geography draws the eye away, to the horizon and the High Plains sky.  The skids are between mileposts 28 and 29, eastbound. On March 14th, at 3:22 in the afternoon, a dust storm kicked up by a cold front moving east from Colorado suddenly swept over the eastbound traffic. Visibility darkened to zero and vehicles began to crash. The collisions continued for fifteen minutes. By the end, 71 vehicles had become involved in the pileup in the blinding dust, with 46 …