Originally Posted by
Praxis
Actually, I think I'm somewhat unique in that I include all the time. It's not like the waiting at lights magically doesn't make me later for work. I'm thinking of changing it up, though, because I'm curious how much of my variance in elapsed time is due to me, and how much to the lights.
Just skipping time spent at lights isn't enough to compensate for them since you're also spending significant time decelerating for them and accelerating from a stop.
For example on one morning commute I took 47:38 of wall clock time to cover my 11.8 miles of which only 6.6 minutes were at zero speed although 10.9 minutes were at zero cadence and 12 minutes were at zero power (I spin the cranks a little to down shift approaching lights).
Looking at the ride plot one acceleration from 0-20 MPH takes about 18 seconds which wouldn't be bad; although the route includes 10 stop signs and 24 traffic lights of which only one is a right turn where I can proceed when the light is red. That ride seems to include 17 stops which would be 306 seconds accelerating or another 5 minutes that aren't at full speed.
Then there are indirect effects - stopping lets you recover and go harder when you restart; but stress is roughly proportional to the square of power so accelerating at 2-3X your one hour power is 4-9X as hard as just cruising along for the same time period.