weeks or months or years in advance (which is the time frame that a permit system would need to function on Mount Everest).

These big traffic jams occur because everyone is on the mountain, waiting for the weather to clear enough to allow climbing to the summit. So when it does clear enough to climb, *everyone* goes for it all at the same time. And that's how you get a line 200 people long, perched on a mountain ridge over 28,000 feet above sea level.