Slowing to 2-3 ft/sec. is different from coming to a complete stop because if you stop, you must start again and it takes few seconds (especially if you don't have automatic transmission) and that's the reason you don't do complete stop even if when you should. That few seconds might save your life. That's the reason Stop sign and Right of way sign are two completely different things and you are required to do a full stop at Stop sign.