Wow...lots of questions and comments. Ygmir has answered some, but I'll chime in FWIW.
For UnJon: There is no lane from the highway because that'd be unfair. So you come tooling down the highway and zip all the way to willcall in your special lane (if there's no wait). Since there's special lanes to exit from Will Call into the processing lanes, you've effectively jumped the whole line. And once that special line becomes full/backed up to the highway,the reverse is true; you are all just sitting there in your single lane, while all 12 lanes of the main part of Gate road creep forward past you. The best thing to do is to create the most paths to the first decision point. That sorting/decision point is at the Apex opening Yggie mentioned. If you got tix, you are pulled forward to be processed with search/tickets torn, etc. If you need willcall, you are directed there. It LOOKs chaotic, but it's actually not. It's honestly the result of some very smart people studying queueing a LOT and coming up with that method. Seriously.
DLot is the lot where Gate folks park you if your shit is somehow not sorted and dealing with you is going to take more than a few minutes. Things like: fake ticket, lost ticket, "I need a handy from someone in my camp can you call them?", "I don't have an early arrival barcode but they'll bring me one", large vehicles/art cars needing dismantling for search, etc. They have the time, experience and resources to sort you out or have you removed from the event site.
The stack lot is a temporary construct used only on opening day/night. It is NOT DLot. If you arrive at the Gate on opening day and you have everything in order except you don't have an early arrival pass, you've jumped the gun. If it's more than a couple hours early, you'll be sent packing back to Reno; Gate doesn't have infrastructure to support you hanging at the Gate. As opening get closer, you are "stacked" in a lot for when the Gate opens. Gate does this in a way that is first in/last out. Read that again: First in/last out. The judgement is that if you got there real early, you didn't follow instructions NOT TO COME EARLY. That means you'll be the last person let out and into the city. You can probably plan on that being on Monday morning some time considering the traffic at the gate. People that did their best to time it correctly but arrive just a tad early will be the first ones, along with people in the regular gate line, let in as the Gates open because they followed the rules. We balance letting people from the gate line in with emptying the stack lot once the gates open.
Will Call has two components: the Will Call parking lot and the box office itself. The Box Office has made great strides in improving their speed in service over the last few years. The Will; Call lot has been largely unmanaged and left to participants to park and organize themselves. This has resulted in abandoned/lost cars for hours at a time, blocked vehicles, people partying in cars after they have their tickets, etc. Typically Gate comes along later in opening and imposes some traffic control as a last resort. This year Gate will affirmatively control and manage the Will Call lot the entire time. Expect it to be much more organized and efficient, but a whole lot less ass grabbing. Get in, get your ticket and get in the fucking city.
Gate Perimeter & Exodus can always use volunteers, especially those that have been to the event before and have great ideas on how to improve things. Interested in signing up? Check out the volunteering section of their website here for info: http://gate.burningman.com/volunteering.php
The fox provides for himself, but God provides for the lion - W. Blake (attribution corrected)