While there are worse drivers in some cities, Pittsburgh drivers are absolutely awful. (See The Pittsburgh Left.) Apparently, driving school doesn't actually teach people what they need to know, or they forget it too easily, or they simply don't care. It's time for a review of commonly ignored driving laws.

Have you ever seen the Do Not Block Intersection signs? You may assume that, like No Turn On Red, it is perfectly fine to block any intersection not marked with a Do Not sign. But it's never legal to block an intersection - these signs are intended to be placed where this is frequently a problem, to remind drivers of this law.

What exactly is "blocking the intersection"? Ah. This is the part that nobody remembers.

Here, I'm the green car. I'm trying to turn left, but the other lane is full of stopped cars in heavy traffic - none of the red cars are moving. The blue cars are at fault here: they should not have pulled up into the intersection if they couldn't move through it (if the cars in front of them weren't moving). Because of their impatience and desire to move forward 10 feet further to wait, I can't turn left, and all of the poor yellow cars behind me have to wait unnecessarily. Thanks a lot.

The impatience of the blue cars has gained them nothing, but has caused worse traffic in my lane. And yes, they're blocking the intersection.

But there's another way to do it:

The traffic light has just switched. The red cars, all stopped from heavy traffic ahead of them, have just received a red light, and I've just received a green light and would like to go straight. But the blue cars pulled into the intersection. They should have waited until there was room for them on the other side. Now, the yellow cars and I have to wait unnecessarily for the blue cars to move, which may not even happen during this light cycle. We're forced to wait longer, possibly causing more traffic problems.

The blue cars are, once again, blocking the intersection.

Now you know what that is. Don't do it. Thanks.