Once you pass the first aid station, do not try to work your way through traffic until after you clear the top of the Ws.
To elaborate on this, you need to properly seed yourself within your wave at the start (4:00 puts you in the back third or so of wave 1, but the front of wave 2) and how far up Ruxton and the spur you run will further determine the group you will be "running" with up the Ws. Once you are within this group, STAY THERE. You will hit congestion as you transition into the Ws; do not get frustrated. It's ok to pass if your whole line is moving around someone who has mis-seeded themselves, but otherwise stay in line as you will need that energy later on. Just be patient.