Greater Greater Washington

Skybridges don't make the connection

It sounds simple and appealing. Your city has a major road with a lot of traffic, but city planners and citizens want to make it more pedestrian-friendly, encouraging more walkable stores in place of purely big box strip development. How about pedestrian overpasses? With a walkway, people can cross in complete safety and not interfere with the existing traffic. You can even build new stores with entrances on the second level, so that people can walk directly from stores on one side of the street to the other. What could be wrong with that?


Vision of the future from GM's "To New
Horizons" exhibit at the 1969 World's
Fair.
A lot, actually. This was a topic of discussion and disagreement at Wednesday's Rockville Pike community meeting. One member of our table, a former urban planner, felt very strongly that new development should not impede the existing traffic, and heavily used at-grade crosswalks would indeed slow down traffic. The solution, he argued, was a system of pedestrian overpasses.

But skybridges connecting retail above the street simply don't work, and many cities are actually removing the ones they built in the 1970s. Elevated walkways as an urban design (or even suburban design) element are one of those 1960s ideas that, like ubiquitous freeways criss-crossing the city center and single-use zoning, we now realize to be detrimental to a well-functioning city. In fact, elevated sidewalks were one of the centerpieces of the "To New Horizons" film by General Motors at the 1939 World's Fair that inspired a generation of Americans toward a shiny future that ended up destroying their cities. (Fast forward to about 20 minutes in to hear about the skybridges.)

Freeways, skybridges follow a similar principle: we should separate uses. "Put the people with the people. Put the business with the business. Put the industry with the industry." Separate the cars from the people so the cars can go fast and the people stay safe. But as we now know thanks to Jane Jacobs and others, separation is dangerous. Separation means there are fewer "eyes on the street" in any one place. Pedestrian overpasses in Minneapolis make the sidewalks more dangerous. Overpasses themselves can be dangerous, keeping people enclosed in a small space that may be empty much of the day and an appealing spot for crime.

Skybridges also foster less public investment in the street. After all, if people are supposed to cross upstairs, we don't need those crosswalks any more. Maybe we can get rid of this light. How about an extra turn lane in front of this new complex? Wouldn't traffic move better with a flyover ramp in addition to the walkway? And before you know it, the street that was formerly a suburban arterial has practically turned into a freewaythe exact opposite of the boulevard citizens want. Once you take away pedestrians, there's no reason to engineer what remains for pedestrians, and the cycle of auto dependency gets deeper.

That's particularly bad because people often don't use skybridges even when they are there. Pedestrians generally don't want to climb two flights of stairs on each end just to cross a street; they will take the shortest path. When leaving the meeting, I crossed the Pike at Bouic Avenue, where there is no crosswalk, instead of trekking a whole (long) block north, out of my way, to Halpine Road which is farther from the Metro. After all, I only had to cross three lanes, then wait at the island, and cross three more.

A 1960s city planner would say that means we need a fence to keep pedestrians off the street. A 21st century city planner would say that means we need a crosswalk, a traffic light, and a better pedestrian refuge in the median. People will walk across the street whether there are elevated walkways or not. The best thing we can do is design the street for it, balancing the pedestrians with the traffic so neither is unduly inconvenienced.

Right now, Salt Lake City is grappling with a proposed skybridge across Main Street. Denver's are almost completely deserted and many are neglected. Des Moines' Skywalk has caused 60 percent ground-floor retail vacancy rates. As Rockville tries to make its Pike into a low-density urban environment, similar to the density of some of the mid-size Midwestern and Mountain West cities, it should turn away from GM's 1939 vision and toward true new horizons without skybridges.

David Alpert is the founder and editor-in-chief of Greater Greater Washington. He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He now lives with his wife and daughter in Dupont Circle. 

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I grew up in Minneapolis, and as much as I love that city, the extensive network of skyways there aren't doing much for the streetlife. City leaders there are starting to see the light (great find on that MinnPost article - they do excellent work), but they rightly acknowledge that the city made a bit of a deal with the devil in order to keep downtown alive when jobs were leaving. They fostered the skyways and promoted them as an asset for tenants. Now, Minneapolis can be more self sustaining and truly urban, but it has to deal with the skyways that probably saved the downtown from being largely abandoned for suburban office parks.

As far as modern applications go, I think there is still a very limited role for skyways, but certainly not in any urban context. Their role should be in adding connections across otherwise unbridgeable divides, such as freeways or rivers and the like. Still, if I were to parse the semantics a bit, those would likely fall under the category of 'pedestrian bridges' rather than true skyways.

by Alex B on Feb 28, 2008 11:22 am • linkreport

I'm originally from Minnesota, but now I live by the Twinbrook station in Rockville. I actually really like the skyway system in Minneapolis. I think it can work well in a densely packed urban setting, as I think it does in Minneapolis. I also don't think it's at all bad to walk around at street level in that part of the city.

But, I don't see how it could possibly work in a suburban area like Rockville. One of the big reasons it works in Minneapolis is that there are a lot of businesses at the same level at the skyways. You're not constantly going up and down stairs. Multi-level buildings are built right next to each other, or directly across streets. That wouldn't be the case. You'd just have a lot of ugly, annoying pedestrian bridges.

I'd say Rockville Pike is a mess. I'm only a couple blocks from the Twinbrook station, but its a pain to walk there, since I have to cross the pike. Of course, I still do, because its just as much of a pain to drive there.

by Andy R on Feb 29, 2008 4:19 pm • linkreport

I'm from Calgary and hte plus 15 system works like a charm

by zero on Mar 19, 2008 1:04 pm • linkreport

Skybridges are a disaster. San Francisco, an amazingly walkable city full of vibrant neighborhoods and bustling tourist districts, has one major dead zone: the massive Golden Gateway-Embarcadero Center redevelopment project, occupying some of the city's (and the world's) most desirable real estate, absolutely deserted at street level any time other than M-F 9-5. Because of skybridges. The Redevelopment Agency's big Japan Center project, also skybridged, is much less successful than everything around it, but at least not totally dead.

by Alan in SF on Mar 19, 2008 1:18 pm • linkreport

I'm from Denver and didn't even know we had skybridges...well, I guess I did, but I never really considered them skybridges.

They work pretty well on the Las Vegas strip, though, right?

by Herb on Mar 19, 2008 1:34 pm • linkreport

I'm from Minneapolis, and I don't see any problem with the skybridges. One of the reason we have them is that it gets f**king cold here. But when it's nice out, we all walk on the sidewalk.

by asdf on Mar 19, 2008 2:52 pm • linkreport

Ok, I read the MinnPost article. It has some interesting points. You link to it in the context of the sentence "Pedestrian overpasses in Minneapolis make the sidewalks more dangerous. " Can you point me to the section that supports that sentence?

I see this sentence:

But at night and on weekends, people are thrown out onto barren and neglected public sidewalks. A social hierarchy develops: the wealthier classes in private spaces on weekdays; poorer people out in public spaces at all hours.
But that doesn't really support your sentence. What is the basis for your claim that crime is increased because of skyways?

by crack on Mar 19, 2008 3:26 pm • linkreport

Herb: People use the Vegas skybridges, but the biggest problem with skybridges is that they cause buildings to turn inward and suck the life out of the street. The Las Vegas Strip is one of the worst streets in the world for inward-facing buildings: each casino is completely designed to keep people inside and not to engage the outside at all. It's not the skybridges' fault in Vegas, but it's part of the same architectural philosophy that gets you such a non-urban place as the Vegas Strip.

asdf/crack/whoever you are, I think you're right that that article doesn't specifically speak to safety. Maybe I posted the wrong link. Still, skybridges do reduce safety for two reasons: barren streets are more inviting targets for street crime because removing people from the street takes away "eyes on the street," and second, cars are less likely to watch out for pedestrians if they aren't expecting to see many pedestrians.

by David Alpert on Mar 19, 2008 3:47 pm • linkreport

Skybridges are worst when they're not open to the public --that really takes the life off the street. They allow people to avoid the lack of streetscapes, sidewalks, lighting and other amenities that make for a quality pedestrian environment. That said; when they're open to the public, in non-temperate climates, or where there isn't a viable street crossing, I think they're OK. There's a lot that's made of their negative impact on street level businesses but from my view that's where those street level businesses were marginal anyway.

by etienne on Apr 2, 2008 1:07 pm • linkreport

Skybridges work best when the street level is undesirable for some non-travel-related reason (like really intemperate weather). And they don't seem to work that well even in Minneapolis.

However, I've seen one place a long time back where they seem to work well, though I can't remember the location. This was a place where the skybridges were *shorter* than the ground-level trip (and open to the public, of course. It is a place where the ground-level terrain is really bumpy -- with a steep valley -- and the skybridges run "flat", starting at street level and ending at street level, but being at higher stories in the intermediate buildings which are built on lower ground. They are open to the public, of course. The overpassed streets were kind of abandoned, but all the buildings had been redesigned to use them as truck loading/unloading access points, with the skybridges as the main pedestrian entrance and exit, and it worked.

Pretty rare situation I would imagine. As Alex B says, I'm not sure those exactly qualify as skyways, either.

by N on May 5, 2008 9:45 pm • linkreport

Nice topic!

I need a design for a skybride to connect two buildings. Size: 26m long & 5 m high. Does anyone have a readymade solution? Please help!

jay5313@gmail.com

by Jay on Jun 3, 2008 11:56 am • linkreport

Part of the reason why the Vegas Strip was inwardly designed is because of the hot and dry climate. The most popular casinos are the ones that are inter-connected and the less popular ones require a trip on the city street. Nonetheless, the Vegas Blvd sidewalks are always busy.

by Andy Chow on Mar 6, 2012 4:06 pm • linkreport

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