Yeah people drive slow because they aren't in a hurry. I don't understand their logic. When I'm on the road, I stay as far away from people as possible. I go when the light turns green (so easy to read opposing directions traffic lights to the point I know when it's going to turn green), and I keep right except to pass.
Fun fact about the siren/alarm. I had an alarm hooked up to my horn. It did not resemble police/ambulance etc, but boy it sure made people get out of the left lane.
Regardless of whether or not I'm in a hurry, it's incredibly annoying to be stuck behind people that aren't aware of their surroundings. I often hear people use this as an excuse, "are you in a hurry?". No I'm just trying to get off the ****ing road away from all these mongoloid soccer moms.
My main aggravation comes from drunk drivers (I see it a few times a month), texting and driving (I see 10+ a day, swerving, sitting at green lights), and people who drive under the speed limit. And especially people who drive in the passing lane without passing.