This past week, The Seattle Times reported more than 400 responses to an article about the City increasing its annual fee for the Macy’s skybridge. Astonishing! I can only hope that something vastly more important — like, say, the Gulf of Mexico oil spill disaster — engendered at least that number.

For some reason, here in Seattle, pedestrian skybridges seem to inflame people’s passions. These appear to range from “Why the hell not? My elderly aunt loves 'em” to “Hell. No. Never. They are a pox on the city.”

My view is a bit more complex.

First, for the record, there is no tenet of city planning that has declared skybridges to be some evil force that must be banned from urban society. On the other hand, there is no solid evidence that they benefit a downtown either. As with many things, the issue is not black and white; it depends upon the situation.

An individual skybridge is, by itself, a fairly benign presence, despite claims in some quarters that these structures block views and cast shadows. Within downtowns, people are constantly moving; what might block a view or cast a shadow for a minute to two quickly ceases to do so farther along the street.

For example, the often-repeated claim that the convention-center bridges block views is simply false. Yes, the view of Elliott Bay is obscured for perhaps a block or so along Pike Street near I-5. But the view opens up again as you continue to walk west. There are no views of the water from points east of Boren, as the angle of Pike shifts and makes that perspective impossible.

Some folks who are obsessed with ridding the city of the scourge of bridges might forget that even the beloved Pike Place Market has a skybridge: the one over Western Avenue. Yet the Market has not seemed to suffer as a result.

On the other hand, pedestrian skybridges can harm a city when many of them are laced throughout a downtown to create a system of second-level walkways. This is seen in the downtown areas of Minneapolis, St. Paul, Cincinnati, and Atlanta. Even downtown Spokane has a sizable network for its comparatively modest size.

The problem with systems of skybridges is not so much related to notions of social engineering, as some might think, but rather hardcore capitalism. The issue is actually quite simple.

Very few cities have enough demand (aka density) to support two separate levels of retail shops, services and restaurants. (Very large and dense global cities like New York, Tokyo, and Hong Kong can and do.)

Retail shops, service businesses, cafes, and restaurants absolutely depend upon both visibility and accessibility from passersby who are on foot. This has been the case for centuries. Many also benefit from continual exposure to vehicular traffic as well.

So when a skybridge network begins to form, retailers have to decide whether to stay at the street level or move upstairs onto the skywalk system. Some move up, which confuses customers and dilutes the marketing synergy that results from uninterrupted, side-by-side retailing. Over time, the street level gets less and less interesting, with vacant stretches that simply aren’t very appealing.

But what also happens is that the second level is often weak. Those shops no longer have visibility from the street level. And what’s worse, because they are often located within corridors that slice through office buildings, they must close at 6 p.m. when the buildings do. The result? A downtown that has little activity in the evening; it slowly becomes merely a 9-to-5 work place. This is exactly what happened to places like Spokane. And it has taken that city decades to reverse that trend.

What’s interesting is that some cities with downtown skybridges have seen street-level retail gradually come back and the skybridges increasingly left empty. The second-level system simply can’t be sustained over time. The very nature of the system is its own worst enemy; it fundamentally depends on private property. Unlike streets, the bridges are not maintained as part of a public realm forever available to all.

As buildings suffer tenant turnover during economic downturns, skybridges are often left connected to nothing. For example, there are two skybridges in Spokane that now dead-end; one runs into a building with an entrance that has recently been closed to the public, and the other leads to a now-dead department store.

In Atlanta, retail energy has migrated from the downtown, which is shot through with long bridges, to midtown, where the city has determined that skybridges are not to be permitted. Midtown is now more lively than downtown as it is chockablock with cafes, shops, museums, and galleries — all at street level.

Over the years, Seattle has had its own little forays with skybridges. Two of the less used and useful were removed. One led from a garage on Fifth Avenue to the Olympic Hotel. The other spanned Fourth Avenue and also went to the Olympic. Few people used them; most had no clue how to even access them. Good riddance to those. Early development concepts for Westlake Center had the complex tied to the then-Bon Marche (now Macy’s) and the long-gone Frederick & Nelson department store. Thank goodness those were nixed by the City.

But the handful that remain are isolated, are often a number of stories in the air, and are marginally convenient to most people. The one at Macy’s is only lightly used. Interestingly, the few that we have are in areas where the sidewalks hardly suffer from lack of activity. On most weekdays and weekends, the streets are teeming with people, street entertainers, lively storefronts, and sidewalk cafes.

Downtown Seattle is in no danger of being invaded by an abundance of skybridges; city policy discourages them even though they do occasionally get approved.

Systems of skybridges can do real damage to downtowns. Individual bridges? No so much.

As for the seemingly absurd fee that Macy’s is being charged, there may be a good compromise. Cities have a legal right to charge private parties for using public rights-of-way for their singular use. But while $300/per year is obviously a pittance, $30,000 seems pretty exorbitant for a piece of space in the air that can’t be much more than a couple thousand square feet. Be reasonable, City of Seattle, not grasping.

Perhaps in lieu of a fee, Macy’s could contribute funding to enhance the presence of street cops at the socially (and often criminally) problematic intersection at Third Avenue and Pine Street, right outside its doors. That would benefit everyone, including the store and its customers.