It shouldn't take that much energy to stop if you are cycling at a reasonable speed. If you are cycling, through an area where there are pedestrians, at such a speed that you cannot stop reasonably quickly, you are cycling too fast.
> It shouldn't take that much energy to stop if you are cycling at a reasonable speed.
I'm going to read between the lines here.
First, you're correct, it takes next zero energy to stop. Squeeze the brake levers and you're done.
What you and the GP seem to be referring to is the energy to start up again from a dead stop. For most people, this means getting back up to putting out around 1.5 W/kg, which I agree is easy. (This is your typical bike commuter.)
For the rest of us that road cycle, this means getting back up to putting out 2-4.5 W/kg, which requires a pretty hefty instantaneous power expenditure if the cyclist wants to get back up to speed quickly. Note that this is still a reasonable speed in many situations, but it is not a reasonable speed for cycling in an area with pedestrians.
I have three rules for red traffic lights and stop signs when cycling:
1) If the light is red, I stop. If the light does not have a sensor, wait for the green. If the light does have a sensor and will detect me, wait for the green. If the light does have a sensor and does not detect me, I have no other choice than to wait for an opening to cross the intersection against a red light. (There are several such lights on some of my cycling routes that I cannot realistically avoid.)
2) I stop at stop signs when there are any other vehicles at intersections controlled by stop signs.
3) In rural areas, when there are no vehicles within visual distance at intersections controlled by stop signs, I slow down and check several times for vehicles in each direction. If there are none, I'll simply pedal through; otherwise I will stop. If I'm pedaling through slowly I'm starting the crossing at less than 5mph, anyway, which is usually slower than most cars roll through stop signs.
