You can do this off the bat or wait later on... (I waited.) You can do this with an AI or solo
You will need
1 Truck
1 AI (or 2 if you did it off the start)
That's it!
What you will need to do is Drive to the right side of the Freeway and park the truck at an angle as to trap yourself in a triangle (solo) or straight like in the video with partner ai's watching your back for a straggler.
Then just crouch so the zombies can't see you the 2 minutes will fly in an instant I tried running in a tunnel and hoping to last 2 minutes running with alooot of stamina snacks (twinkies) and it was hilariously hard so if you want it simple as I ended up doing just follow those steps.
I included a youtube video for those who like to just view it (xbox one app) and pictures of the map areas