If the traffic is super slow and really heavy as shown in this picture and you need to chage lanes, you need to turn on your turn signals to whichever lane you changing, and slowly just go closer and closer to the lane you going to change, but not too close, but at the same time, between a gap (between the car in the front and the one in behind in the lane you changing). The car next to you (behind the gap) probably going to stop and let you in. If the driver is a jerk or not paying attention, just wait to the other gap, and probably, this time someone with let you in.