[mortehu]

If the were no lanes and everyone was just driving in a huge field with no brakes, your analogy would make more sense. When there's only a few cars nobody would have to touch the steering wheel, but as the number of cars increases it gets more complicated, both per car and in aggregate.

[jjk166]

Satellites do travel in lanes (orbits) and do have brakes (maneuvering thrusters), so the analogy is pretty spot on. Changing your speed (the magnitude of your velocity) to avoid a collision is also a collision avoidance maneuver, functionally equivalent to changing the direction of your velocity.