Over at Imagine Metro Kevin Picken has proposed a cable-propelled transit / urban gondola / cable car connection between Washington’s Dulles International Airport and an upcoming rail link.
Picken’s thesis is intriguing.
According to Picken, the upcoming Phase II of the Silver Line Rail Link works out to a per foot cost of $44,856 USD. The vast majority of the line would be built along a traffic median in the Dulles Toll Road but would divert from the median to service the airport then return to the median.
You can note the line diversion in the above map as the dotted U-shaped line passing through Dulles Airport. Image via Dulles Metro.
Pickens calculates that the difference between merely continuing the line along the median and the airport diversion to be 7,359 feet. Opting to stay in the median and by-pass the airport would result in a potential cost savings of $330,095,304.
He’s also quick to note, however, that such an option would eliminate any direct connection to the airport, thus negating a great part of the appeal of the line.
Which is where gondolas come into play . . .
Pickens assumes that a gondola connection to Silver Line Phase II would be 6,591 feet. Using Whistler’s Peak 2 Peak as a benchmark, Pickens calculates a per foot cost for a 3S system to be $3,600 – which is reasonable, but may not be accurate given the cost escalations we’re seeing when applying the technology in urban environments. That works out to ~ $25m USD for a gondola connection.
Deduct $25m from $330m and you’ve just saved a whopping $305m USD while still providing the direct airport link.
I like this concept . . . a lot. My major concern, however, is with the cost estimate. As we’ve seen before, cable in urban environments (at least in westernized democracies) have a tendency to meet with a lot of scope creep and cost inflation. If we were to use the Burnaby Mountain situation as a benchmark, we could assume a potential cost escalation of up to 340%.
Yet even still that would only result in a cost of $85m USD for the gondola connection thereby saving the Dulles Silver Line approximately $250m USD.
At numbers like that, Picken’s idea deserves a lot of attention.
3 Comments
I’ve been to Dulles and as I recall, it is surrounded by highways and lots of space. This point alone could bode well for the project, as it may eliminate much of the privacy concerns that are so often raised in these situations.
Wouldn’t the FAA take issue with any project involving towers and cable around and in an airport? I would think that any aerial technology would be a non-starter because of this (although a cable car could probably offer similar benefits without this issue?)
I don’t know all the details of the concept, but it’s probably a moot point. The tower infrastructure would be no higher than the airport terminal, surrounding electricity towers or any elevated expressways/onramps.
Probably nothing more than 4 storeys off the ground.
But again, I don’t know for certain.