There's no need for it to be exclusive. If there is more than one person who wants to lay out the track, they can often work together and come up with a great lay-out incorperating ideas from both people.
We used to make tracks up on the fly all the time. Craig coming up with track plans in advance is qute a modern idea; he only started doing that 5 years ago or so. We used to all go out on the track together, and have three or four guys colaberate to build a track on the spot. It's defaintely much easier for everyone else involved if the lay-out is done beforehand, since the entire track can be built at once, instead of following the guys around as they come up with the lay-out.
I'm not concerned about coming up with a track; if other people want a vote or anything, feel free; I'll just leave it up to those who care.
