The traffic jam occurs near the Beijing end on the Beijing-Tibet highway. I'm sure the Tibet end is fairly clear since they are couple thousands of miles apart (http://en.wikipedia.org/wiki/China_National_Highway_109). It's like the traffic jam near NYC on the SF-NYC highway (if there's one) having no impact on SF.
That's a great expressway. I remember being on mountain roads in China that were outright dangerous only 5 years ago. When I went back last fall, I was amazed at how much speed we could make on those freshly asphalted roads. China has progressed a lot wrt. infrastructure in just a few years.
on the slashdot comments they were saying that the jam has lasted 9 days but it doesn't take that long to get through it. Rather there has been enough new traffic to sustain the event for 9 days.