Same here. I'm more concerned with how long it takes me to get somewhere instead of how fast I'm going. I spend a lot of time waiting for lights to change or other traffic to know that whatever average I have would be higher without the waiting.

I do remember seeing one of those Big Brother trailers once with the radar gun and speed display on it, and was pleased to notice I was able to hit 20 MPH without a tailwind or going downhill. But I can't maintain that for long.