On motorcycles you can be just a little bit more agressive, but selectively.

There's enough power to assert high speeds, and take the lead with quick acceleration, but due to the amount of surface area in contact with the ground, motorcycles have lower agility than bicycles, based on the weight that gets thrown around.

With most motorcycles weighing well over 200 pounds, depending on speeds, the usual turning radius cuts a pretty wide arc (not very maneuverable, ultimately), and stopping too short will throw you off the bike. You just lock up the tires, or peel out if you don't finesse the amount of force in play.

They can do more than a car, in terms of turning and stopping, but it requires agility, dexterity and practice. Whereas with a car you can just slam the brakes, and toss it in any gear, do whatever, and not even think about balance.

So, in a situation where you gain a feel for the attitude of some random car, and the driver is radiating the demeanor of a total dickwad, there are three choices. A. Stop, reroute, and go anywhere that fucker isn't. (the best, and most common decision, more than you might ever know) B. Clutch the transmission and rev loudly, to see if they know you exist, which often doesn't work because people listen to music and mostly try to ignore the world around them. C. When they inevitably don't respond to options A & B, release the clutch, and rev the engine to launch in front of that prick and blast off. Fuck the world.

People just really don't like to give other people choices, so you wind up doing a burnout in front of them, because they keep stepping on your toes. Hurts me more than it hurts them. Such is life.

Interesting to know about the turning radius issue. Bicycles can cut very sharp, and I suppose that's a function of both mass and velocity. (Possibly the lighter bicycle is easier to tilt over into a tight turn, driven down by the rider's weight, while the motorcycle has to tilt under its own weight.)

Ultimately, though, on a city street my gut says that motorcycles are in pretty much the same situation as bicycles, or better. Not sure how the stopping distance compares, but what a motorcycle lacks in being able to swerve, it should make up for in power. (Different benefits in different situations.) I believe part of why drivers don't see bicycles is that bicycles are usually ridden on the right side of the right lane. But I have never ridden a motorcycle, so my gut could well be wrong. :-)

(Highway, that's a different beast. I care less about how loud motorcycles are out there.)

So I guess here's a question: Should bicycles be equipped with constant noisemaking devices?