Quite honestly, somone with a background in traffic management and queueing theory is one of the FEW people I would listen to about their opinion on Fastpass.
I used to do some of the same sort of work back in the days of MicroCyclone. Resource availability, queueing theory, and cyclic crew modeling. That was back in college.
An intersection is a shared resource. E-W traffic cannot use it at the same time as N-S traffic. Signal timing is critical to traffic flow. Correct signal timing can INCREASE throughput.
Anyway. Fastpass is not a horrible flawed system - inherently. Where it is flawed is in how it is used. It is a time shifiting system.
If some people used fastpass to hold a "virtual" spot in line, and insted went and shopped, then line lenghts would not increase over what they are now. The wait time is shifted to shopping time.
If EVERYONE used fastpass, and instead of spending more time shopping (or walking around, or whatever) they spent that time waiting in line for other attractions, the OVERALL wait time would not change. Intead of you and me both spending 30 minutes to wait for attraction A and B, you would wait 15 for A (where you have a fastpass) and 45 for B (where I have). I would wait 45 for A and 15 for B. We both spent the hours in line, but shifted it from one attraction to another.
The flaw (if you want to call it that) is when SOME people (not all) use fastpass to wait in another line. Then you are shifting the wait time from one person to another. The people using fastpass are getting though the lines quicker, while the people not using fastpass are taking longer. THIS is how fastpass is currently being used.
Is it 'fair' to people not using fastpass. Maybe. If you want to tour the parks in a linear fashion, and go on attractions at the spur of the moment, it's not going to work out to well for you. That does not mean it's unfair, it just means you have made a choice to tour the parks your way, and now its going to take longer.
-dave
To put it another way, the number of people getting on the rides hasn't changed. However, now guests can be in two places (and depending on how far out the return windows is on their fastpass, three places) at once.
Because Fastpass isn't used at the same efficiency by every guest, it is an unbalanced system that favors those people more familiar with it. However, the aggregate overall wait times should remain constant with or without Fastpass. This assumes that the efficiency of the ride (guests per hour) is unaffected.
From an implementation standpoint, the ride doesn't determine Guest Per Hour based on whether or not the guests used Fastpass or Standby. The issue here becomes are guests more likely to experience a ride using fastpass then they otherwise would if Fastpass didn't exist and the Standby line was slightly shorter. Then there's the opposite effect. Are people turned off by the longer Standby times and opt not to ride the ride.
If you look at an attraction like Toy Story Mania, assume the following on Day X:
The average wait time for Fastpass guests on Day X is 15 minutes
The average wait time for Standby guests on Day X is 120 minutes
If Day Y is identical to Day X in every way, except Toy Story Mania is not operating Fastpass, assume the following:
The average wait time for Toy Story Mania is 60 minutes.
Will there be guests that go to the park on Day Y that will decide to not go on Toy Story Mania because the wait is 60 minutes? Yes. Is it safe to assume that some of these same people would go on Toy Story Mania with a Fastpass on Day X if the wait was only 15 minutes? Yes. It's also safe to assume that if they won't wait for 60 minutes on Day Y, the won't wait for 120 minutes on Day X.
Now, the other side of it. On Day 6, everyone that is willing to wait 120 minutes, would also be willing to wait 60 minutes. However there are likely people that would not be willing to wait the 120 minutes that would be willing to wait for 60 minutes.
An alternative to this system that would probably benefit everyone, but may also complicate things even further would be having Fastpasses assigned to your pass upon entering the park. Meaning that if you enter the park at 9, you would have your available fastpasses for the day assigned to your pass, and you would have more favorable times than someone that entered the park at 11. That effectively happens anyway, but this would eliminate the "fairness" aspect of it.