Med Ship Man by Murray Leinster — Read

Calhoun was in very bad shape when the sports car came to the end of the highway.

First, all the multiple roadways of the route that had brought him here were joined by triple ribbons of road-surface from the north. For a space there were twenty-four lanes available to traffic. They flowed together, and then there were twelve. Here there was evidence of an enormous traffic concentration at some time now past. Brush and small trees were crushed and broken where cars had been forced to travel off the hard-surface roadways and through undergrowth. The twelve lanes dwindled to six, and the unpaved area on either side showed that innumerable cars had been forced to travel off the highway altogether. Then there were three lanes, and then two, and finally only a single ribbon of pavement where no more than two cars could run side by side. The devastation on either hand was astounding. All visible vegetation for half a mile to right and left was crushed and tangled. And then the narrow surfaced road ceased to be completely straight. It curved around a hillock -- and here the ground was no longer perfectly flat -- and came to an end.