I have found that the more aggressive you are with drivers in busy traffic conditions, the more they tend to pay attention. As said above, tip-toeing across a lane will get you nowhere with the drivers on my commute. I look over the shoulder, give a signal, then I go. If I sort of mess around all apprehensive like I did when I first started riding in traffic, I would never get to change lanes (and would probably get run over) to boot. The drivers on my commute are some of the most backwards, redneck, ridiculous people I have ever seen (Columbia, South Carolina has the worst drivers in the US) and if I am not aggressive as well as defensive, I would not be able to make my commute.

I always signal, and I ALWAYS ride like I would drive. Take the lane when you have to, signal when you need to, follow traffic signs and signals, etc.

Always try to be more of a vehicle than an obstacle.

Joey French