You're driving down a multi-lane road. Traffic is heavy, and everyone slows down. You notice that the lane next to yours is consistently going faster than yours.* You wait for a chance to pull over, and when you finally can, you find yourself stopped, forced to merge back over, because the lane you just entered is closed ahead.

So what happened? Is it just that the grass is greener? Is fate out to get you? Are you just a total loser? YES! But there's another reason, too. It is the Blocked Lane Speed Anomaly.

Consider the location of the merge. Ideally, one would think that both lanes would progress equally, as each car in the open lane allowed one car in the blocked lane to go before them; in other words, taking turns. But life just doesn't work that way. Instead, drivers in the open lane laugh at the drivers in the blocked lane, speeding past them until the rare driver comes along who's nice enough to let one merge over. So you would expect that the open lane would be faster, right?

Nope. The vast majority of the drivers are familiar with the situation. They realize that if they get clear up to the blockage, they may be stuck there. They also know that they can go faster than the cars in the other lane, which gives them a bit of an advantage. So they identify an opening in the other lane (as far ahead as possible), usually slipping in front of someone who's fallen behind the vehicle in front of them.**

This is the cause of the anomaly. Right at the merge, the open lane has a clear advantage, but shortly before it, the blocked lane is faster. As each car in the latter comes close to the merge, they grab a spot in the other lane, generally without slowing down or waiting first. Not only does this mean that the blocked lane will not get backed up or slowed down, it also further slows the open lane.

How to handle this phenomenon:
    If you are, or are willing to become, an asshole, you should:
  • Get into the faster lane as early as possible.
  • Learn to identify the types of cars that you can cut off. Stereotypes are assholes' friends.
  • Remember that you are more important than any of the other people on the road. They're just out driving for fun, but you actually need to be somewhere. The awareness of your own importance will help you get rid of any insignificant guilt over cutting off and frightening any little old ladies. Hell, they're too old to be driving anyway, right?
  • No matter what, do not slow down before merging. If your intended mark closes the gap before them, find another further on. If you slow down and wait, you might as well just go on up to the end. At least there someone might feel sorry for you.
    If you are not an asshole, you should:
  • Get into the slow lane as soon as you recognize the situation. It's okay to do so when convenient, you don't need to stop right where you are and wait for someone to let you in. The best option may be to do the same as an asshole, but choose the first opening you can get.
  • Stay very close behind the person in front of you. Don't be afraid to run into them lightly; that's why they call them bumpers. This will keep the assholes from cutting you off.
  • Don't let the people at the end of the other lane merge. They were trying to screw you, and they screwed up, so let 'em suffer. After all, you're clearly better than they are, since you're not an asshole, so it's okay for you to judge them. Anyway, some fool will let them in soon enough.
  • If the line is especially long, or you're especially angry at the assholes, go halfway into the other lane, so they can't pass you. Prepare to be cursed.
Final notes:
This is probably a phenomenon limited to certain areas. Major differences in traffic patterns would undoubtedly affect the reasoning necessary for the effect.
HHOK or HHOS, as appropriate. Whatever works for you. :)

*It's always the other lane that's faster. Urrgh!
**This is basically the same as line jumping, aka ditching. But at least they didn't shoot you.