Phantom Traffic Jams

Must be busier than I thought on Skull Island.
"one of the great mysteries of motoring has finally been solved;
The issue here is that of phantom traffic jams. You know the kind of thing. You're driving along a motorway, as the case may be, and all of a sudden you're faced with the back of a long queue. You trundle along at walking pace for ten minutes, and then suddenly there isn't a queue any more. What happened there?"