Glen, the new line to the airport and west to Ward Road will be heavy rail commuter, not light rail. RTD is getting SINGLE LEVEL electric MU equipment to run on the new commuter lines.
One of the prior designs for DUS involved putting all the tracks underground. One of the main reasons it didn't make it was the occasional visits by the UP steam locomotives - another was the 4% decending grade into a dead end tunnel. So there was at least some thinking about allowing the UP steamers into the station.........
Originally the DUS project was supposed to be all RTD - but RTD soon realized they wouldn't be able to pay for it so turned it into a "public - private" partnership, which is when the proposal to put the station tracks underground and move the light rail station 3 blocks away appeared - all to allow more space for more profit making buildings. The FRA nixed the underground deal but the light rail did get moved - necessitating a 3 block walk to connect between commuter and light rail trains. Plus, you still can't - and probably never will - be able to get from Union Station to downtown on the light rail without going south to Broadway, get off, and get on another train into downtown. The new west light rail line that opened about a year ago suffers this same problem - you can ride directly to the Union Station light rail terminal but have to do the above to get into downtown, or WALK about 5 blocks to the 16th Street BUS shuttle to go downtown. I don't ever have much reason to go downtown so don't use the light rail at all - but I might if I could actually GET TO downtown ON THE RAIL conveniently from the west. Even the new west commuter line (scheduled to open in 2016) will only go to Union Station - if I'll ever want to go to the airport I'll have to get off at DUS and get on another train to DIA. Don't think I'll be using that much either...........

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