Trapped on the road with no way out!

If there is one thing that I hate merely for the fact that it makes no sense, it is random traffic jams. You're cruising down the highway when all of the sudden you're forced to come to a halt, and then you crawl along the pavement for a few miles. Eventually you come to a clearing and traffic picks up again, congratulations, you've made it out of the......wait a minute....NOT AGAIN. Bam, just like that you're caught up in more congestion, no warning of any sort, no real reason as to why it's happening. This pattern continues for a long while until you finally reach your exit and the situation is over, but why on earth did it occur in the first place? Allow me to speculate and explain how I feel this happens...or not. I don't know and I don't feel like trying to figure it out, the main point here is that they suck because they come out of nowhere and bite you in the ass. Random road jams are AWFUL.