After researching what the plans are for a future Salt Lake Central terminal building may look like, I found this from two years ago:
http://utasupportdocs.com/pdfs/SaltLakeCentralStationDraftEA_AwaitingFTAApproval.pdf
The gist is that the parking lot by the plaza will be filled in with a 120,000 sq-ft, 4-story tall terminal building, which will be shared by Trax, Bus, FrontRunner, and Amtrak. This building will suposedly be funded by UTA and RDA, and will include office space and retail. Enough retail, they claim, to significantly increase ridership.
This is cool and all, but I want something bigger and more iconic than a 4 story office building for Salt Lake's new major train station. After all, if we cannot have the UP or Rio Grande depots, then surely we should be getting somethig even BETTER, right? At least as grand and iconic as the city library... get rid of that unused circle drop off zone and give the building a BIG footprint to work with. Offices and height are fine, but give lots of space to the public for a waiting room, lots of retail, and of course restrooms and the basic amenities.
Speaking of the old UP Depot, I know one of the consulting engineers who worked on site identification for the the Intermodal Hub - he's now a professor down at the Y. According to him, the UP Depot was always the #1 choice for a centra hub, but two things killed that idea:
1) No direct southbound right-of-way
2) Amtrak
The problem with the UP depot is that the tracks going south went right down the middle of 400 west. I believe they are still there in some places. There was no way FrontRunner could ever use tracks in the middle of the street, so the plan was to turn the UP depot into the UP terminal - meaning make all station tracks stub tracks. All Southbound Commuter Trains would have to make a sharp lefthand turn 180 degrees out to the current right-of-way just past 600 west. This meant that all commuter trains would be either north or south trains - no through trains like we have today. Also, it means that commuter trains would potentially need to wait for freight trains, because that junction (called 'Grant's Tower' to railroad people (the unused tower is still there behind the gateway, if you're interested)) is a very busy juction for transcontinental frieight trains.
As designs progressed, Amtrak, which was also to share in the station, suddenly informed the design team that the station tracks would need to be at least 1,400 feet long, because at that time Amtrak was hauling boxcars of express mail on the back of their trains (they no longer do because it never made them any profit). Anyway, there was no way any of the tracks could have been extended to that length, and with Amtrak threatening to pull out the Depot idea was scrapped.
Central Station today allows run-through commuter trains on their own dedicated tracks and a very fast walking connection with TRAX, neither of which the old UP depot would have allowed. It is a magnificent station, and I'm glad it is preserved, but the new Central Station could potentially be so much better. Let's just hope that City and UTA planners dare to dream big.
Oh, and since the picture of the Provo Amshack popped up, here is a terrible link to an original study to use that location for the Provo FrontRunner station. This is from way back in 2000, when planners assumed FrontRunner would run on UP tracks instead of its own. (Note also the Amshack was not yet constructed at that time - the site had only a portable bus-shelter on it).
Hopefully this shows that they did the right thing by building a huge new intermodal center where they did, and not where the former Rio Grande station was (Amshack still is).
http://www.docstoc.com/docs/99806117/PROVO-INTERMODAL-CENTER
Again, I appologize for the poor quality of the link, but it's the only place I could find this document. If anyone has a better link to it, please post!