I noticed myself doing this too. I consider myself a conservative driver. I usually will not allow other drivers to aggravate me. But I do have my limits, and once the driver exceeds this limit, I will do something to let him know it. Convoys Ota thinks people drive in convoys for different reasons.
Slower drivers like to drive in packs because they feel safer from other drivers who are speeding.
They do it for a sense of security. On the other hand, speeders travel in packs to avoid the law. They feel more comfortable breaking the law if others around them are doing the same thing. Reisner also thinks that people travel in convoys in order to avoid getting a speeding ticket. He goes on talking about why some people like being in the head of a pack.