Bus wars!

I've been doing a lot of driving lately (I even had to break for ducks today). And I know we're all in a rush to get to places, and we all have different abilities and reaction speeds; but the one thing that really bugs me is to hang on my tail as close as possible. It's certainly not going to make me drive any faster. So why did a bus driver decide to to get as close to me as possible last night? At first I thought he was only heading off to the parkway, but it turned out he was right behind me, and I know that he certainly wasn't sticking to the agreed speed limit. At one point I thought he might actually be trouble; and kept checking my wing mirrors to look out for a group of pirates fighting a group of ninjas while hanging off the outside of the bus. But no, it turned out he was just taking the bus back to the depot.