A combination of small pieces from comments on another site
Doesn't have to be complicated.
I can sum up the entire thing in one sentence:
If your starter line for a rail network is really bad, you will never get a chance to build your full network, so you'd better make sure your starter line is attractive to a lot of people.
All of the rest of the talk is just explaining WHY this system doesn't qualify (and the 2000 light rail line DID). (For instance, transfers to shuttle buses to get to downtown, UT, capitol = unattractive).
Transfers and whatnot
Experience in other cities has shown that requiring a bus transfer at the end of a rail trip drastically reduces the number of "choice" commuters who will take the transit trip. This is something that's well-enough known in transit circles that arguing with it is akin to asking a geographer to prove that the Earth isn't flat. (In other words, it's common-enough knowledge that people don't even bother to prove it anymore).
The current express buses are, to me, a bit BETTER than the ASG plan. Yes, they're stuck in traffic on both Mopac AND the city streets; but they allow two-seat travel (car, then bus). The ASG plan is a three-seat trip (car, then train, then bus) *AND* the last portion is stuck in traffic.
It's important to emphasize again that your transit "spine" (i.e. the highest-capacity route) must deliver a bunch of passengers to within walking distance of their destination to be successful. Once you have a few of these, you can start talking transfers, but even then, the transfers to shuttle-bus will always do much worse than transfers to light-rail (for instance, Dallas' commuter rail line from Fort Worth ties into the DART light-rail system. Since DART's been on the ground for a long time now attracting its own choice commuters, people are more willing to transfer to it than they would have been to shuttle-buses or even a brand-new rail line).
The "incented somehow" talk is basically the point of using rail - get around the traffic rather than being stuck in it in a bus. That's why the 2000 light-rail plan was such a good starter line (and note: the citizens of Austin passed it; which is something that almost never happens the first time in a rail election) - it used existing separate rail ROW up to Lamar/Airport; then travelled in-street for the last 4 miles or so in order to drop people off where they actually want to go.
In this political climate, the only "incentive" you can promise with transit is reliability/speed - and the ASG plan craps all over this with the shuttle transfer.
(David asks for clarification on three points - #1 being that I support building the light-rail spine first and then commuter rail to the 'burbs; #2 being that Cap Metro is operating on a "build as much as we can afford and hope they will come" philosophy; and #3 being that my point is that if the first line is bad, that ends everything)
I'd say you're right on the f I'd say you're right on the first and right on the third. On the first I'd also add that it's incredibly stupid to provide rail to the people who hated the idea of rail in 2000 while providing buses to the people who loved the idea of rail in 2000. (This plan, even if it ever makes it to its completed state with all of the expansions and whatnot, delivers nothing more than slightly enhanced BUS SERVICE to the densest parts of town - you know, where in most cities you'd be delivering the RAIL service).
Capital Metro's real reason for doing the second is political - and it's spelled Mike Krusee. I think I have some backstory on this in my blog; let me know if you want a condensed version.
They also suffer from the typical disease here of overreliance on macroanalysis and underreliance on microanalysis. By this I mean that, like with air quality initiatives, they think you can "encourage" people to do something; but they never look at individual choices and the existing structures of incentives/taxes/whatever that lead to the behavior we observe today. Like how they do press releases touting the fact that Motorola or IBM are going to encourage carpooling - this doesn't do anything in the real world since the individual's incentive to carpool is still negligible.