There's one thing more annoying than that: The IDIOT who STOPS at the bottom of the ramp and blocks the merge lane forcing everyone else behind him to stop too!
Stupid sh*t like that gets people killed. I've seen it happen.
A lot of people who learned to drive prior to the advent of interstate highways have always had trouble with the concept of merging. Combine that with timid drivers of all ages and you get a traffic jam on the on ramp, very difficult to get on if you can’t reach the speed of oncoming traffic.