There's a balance to be struck between extreme hypermiling and maintaining safety and traffic flow. I have less trouble with pulses & glides than when I used to maintain speed slightly below the speed limit (people hate that). Fortunately you can actually drive pretty quickly with pulses & glides and still get good numbers when you're familiar enough with the roads you're on and what the lights are doing.
By monitoring what's going on behind us we can get a idea as to what speed must be maintained to prevent pandemonium. On a 45 MPH road with a large pack of cars behind me, I'll glide down to 35 MPH and pulse to 55 MPH if there's room ahead to glide back down to 30 or below if a slowdown is required. Most people seem to be okay with that. If no one is behind then I can bust out the crazy stuff like rolling down to 20 on a 45 (if I'm not running late for work
).