The four lane gig could go something like this for TF, FC, PS, PM, TAD, and TAFC......
Instead of running two pair at once as many seem to be thinking, there would be a severe lack of delay between pairs firing and beginning their qualifying and/or elimination passes. As soon as one pair crosses the finish line the next pair fires. There would be a seamless and constant flow of pro and pro-sportsman cars going down the track. They could cut a substantial amount of earth time out of a weekend of racing that way. It also keeps all four lanes prepped and race-ready in case of oil-down. There's no reason to think they would run four cars at once and attempt to eliminate three at a time.
For every other class, though, the goal would be to run two pair at once. Simple math dictates that they could run Comp, Stock, Super Stock, Super Comp, Super Gas, and Super Street in half the amount of time. The two tracks would run independently of each other and there would need to be some way of displaying things like dial-in's and indexes. Many tracks already use dial-in boards located near the water box so the scoreboards are purely for entertainment value. Bracket races at Z-Max could be run from start to finish in a matter of four-to-five hours with this concept.
A few things to keep in mind with the four-lane concept is the need for increased traffic flow out of the staging lanes and at the top end. Also, with double the amount of cars going down the track in a given time demands the need for increased number of safety personel and equipment.
The facility looks absolutely stunning on TV and in photos. Can't wait to visit it in person!