Back to the OP
(or something similar i think)
today I tried something different on my normal route in.

there's a section of georgetown that gets pretty busy in the mornings.
traffic moves along at a steady 20 - 30 mph
i usually pick a path of least resistance, and like water, the pedestrians, taxis, busses, and cars all blur into stationary ojects i simply flow around.

but not today.

today (with this thread in mind) i fell in pace with a medium box truck at about 25 mph. Keeping right off its rear right edge, I slipped in and out of it's draft stream and physically felt myself get pulled faster and faster and the truck accelerated. As it hit the breaks I would slip back out and to the right lane until it had gained its speed again.

I really had an easy time cutting accross to midtown. and at one point, clocked myself going 36mph!! it felt like 16.

Is this what you guys were talking about?
Some sort of speed check?