The starts are staggered ,just get yourself to the front of the wave you are in . You will encounter people in front who have not put their correct estimated finishing time. You will be doing a bit of weaving and bobbing no matter where you start.
Get there early the traffic is shocking in and especially out ,so expect a long sit in your car. I tend to take some bananas and soreen to keep me going before the start and after I will be bringing a sandwich and treats to eat while im waiting in the car park. Good Luck