Pulling together some suggestions from the comments of the series prologue, part 1, part 2, and part 3…
Monorails: Always popular as a technology that can reduce the visual bulk of elevated rail, Alon Levy collected some comparisons showing that purported monorail cost benefits to be mostly illusory. But what about visual bulk? Alon makes a note of the smaller required structure:
It includes a diagram of monorail structures, which can be seen to be quite light and thin. The width of the structure from guideway to guideway is 4.5 meters including both guideway widths, and including the outside appears to raise it to 5.5. Two-track elevated conventional rail structures typically range from 7 to 10.5 meters wide.
Mumbai has monorail under construction:
One long-standing example is Seattle’s monorail:
New York: Commenter Matthew (of Walking Bostonian) offered two photos from New York of mainline rail infrastructure. The approach for the Hell Gate bridge towers over parts of Queens:
Another example is from the Long Island Railroad, with retail spaces crammed underneath a viaduct in Flushing, Queens:
The LIRR shows an example of re-using the space beneath a vaiduct with retail; perhaps without the architectural glamor of the archways in Berlin or Vienna. Nevertheless, it shows the potential for re-using some of the space beneath elevated rail.
Vienna: Neil Flannagan (after looking at Berlin examples) suggested Vienna:
The Queens Boulevard and Berlin examples really seem like missed opportunities we could have had in Tysons: cheap infill retail using the bridge structure as a roof. It would reduce the barrier effect of the median, focus activity near the stations, and set an example of urban form.
This was the solution nobody was looking for because we were so set on fighting out the tunnel-versus- overground plan and trying to keep the project afloat. I certainly was guilty of believing that no viaduct could be attractive, and kept arguing for a tunnel. I was looking at the types without considering design. It’s the same trap that NIMBYs do, wanting to minimize the impact by making a building smaller, rather than better. Damn. Looking outside of the box is why Jarrett Walker is so great.
I would really take a look at Otto Wagner’s Wiener Stadtbahn. The infrastructure is pretty street-friendly. It’s also very well designed, particularly the bridge over the Wienzeile.
Some images from Vienna:
San Juan, Puerto Rico: San Juan’s Tren Urbano was also mentioned in the comments. Google does not have streetview images in San Juan, but a brief Flickr search for CC images turns up the following examples of the system’s elevated structures:
Table of contents:
Neil’s comment is spot on –not using the street as the guide for the Tysons could have helped. Land acquisition would have probably made a tunnel the same price.
You should include the SkyTrain viaducts. For example, the Canada Line in Richmond is elevated over a sidewalk rather than the roadway:
https://maps.google.com/maps?q=Richmond,+BC,+Canada&hl=en&ll=49.17529,-123.136599&spn=0.000984,0.002642&sll=37.0625,-95.677068&sspn=38.963048,86.572266&oq=rich&hnear=Richmond,+Greater+Vancouver,+British+Columbia,+Canada&t=m&z=19&layer=c&cbll=49.17529,-123.136599&panoid=K9BvB_nSdHDGe-OqKqYTag&cbp=12,179.05,,0,0.09
Yes, it is! It’s my favorite rail trail in the state. There are two oerths I go to occasionally, but they’re more heavily trafficked, more residential, and are on pavement. I love that this one is dirt/stone dust, so much easier on the joints, and it’s far more rural. There are enough other runners/walkers/bikers that you don’t feel totally isolated, but there are few road crossings, and those you do cross aren’t busy.