I know the traffic light pattern on my 15 mile commute, so it's mostly around 15 mph steady pace with 1 500 yard sprint, 1 section of 3/4 mile hard riding (to stay ahead of the traffic that will come behind me when the light changes behind me), and about 2 miles where I can either just relax if I want, or fly as fast as I want to push, depending on how I feel that day.