Coasting in traffic is really tricky. I was playing around with it for a little while, looking way ahead and coasting up to lights, trying to keep as much speed as possible while timing it to hit the light when traffic started to move. Then I almost got rear-ended by some guy who was intent on going 60 mph until the last possible moment before slamming on his brakes for the red light. I still try to look ahead and coast up to lights to a certain extent, but I will get back on the gas if I drop more than 10-15 mph below the people zooming up to the light around me. Coasting at 30 mph while others are still doing 60 royally pisses people off and is asking for major accident damage to the rear of your car.