Build parks beneath freeways? Great! Just don’t inhale

In Toronto, crews are busy constructing Underpass Park, a public space beneath what the Toronto Star describes as “a series of shadowy overpasses” on the city’s lower east side. “This is transformative,” Canada’s finance minister, Jim Flaherty, said last May about the project, which will turn wasted land into sports courts, cafes, and benches — beneath elevated structures that carry vehicles to and from downtown and the Don Valley Parkway.

Toronto is not alone in putting public uses on land underneath highway structures. On the recently launched TheAtlanticCities website, Nate Berg wrote an article entitled “9 Cool Projects Under Freeway Overpasses.”

“Cities are beginning to take advantage of these dead spaces as usable parts of the public realm,” said Berg. Besides Underpass Park, he noted, there are undertakings of a similar sort in Seattle; Miami; Portland, Oregon; Wallace, Idaho; Caracas, Venezuela; Zilina, Slovakia; and Mount Wellington, New Zealand.

The first thought that went through my head upon reading the Star and AtlanticCities articles was that despite good intentions, such transformations might encounter problems: namely, exhaust and noise from the roads.

When I mentioned my qualms to Ken Greenberg, a Toronto urban planning consultant with experience worldwide, he assured me that noise is not necessarily an issue. Greenberg sent me the attached photo, which he shot in the Mission Bay section of San Francisco. It shows four young people playing volleyball on a sand court beneath the South Embarcadero Freeway (I-280).

The space below I-280 doesn’t look murky or sinister — the road is far up in the air, and there’s plenty of distance between its round concrete pylons. Trees and grass growing near the sides of the volleyball court look green and healthy. There’s even a bench, installed apparently so that spectators can sit and watch the games.

“It is actually quite shielded from the noise above,” Greenberg said of the San Francisco recreation space.  He added: “I have high hopes for Underpass Park.”

The decibel level, in other words, may be much less troublesome than I had instinctively feared. In any event, it should be easy for engineers, officials, and the public to get a sense — before decisions are made — of whether noise will make projects like these unviable.

Vehicle exhaust, however, is a more difficult problem to get a handle on. Obviously, volleyball players would not be jumping up and down beneath I-280 if they believed they were breathing air that was going to damage their hearts and lungs. And certainly the authorities in Toronto do not expect people to need medical attention because of time spent in Underpass Park. (The first phase is to be finished by year’s end.)

Christopher Hume, writing in the Star, predicted that the 2.5-acre park, designed by the landscape architecture firm Phillips Farevaag Smallenberg, will be “open, accessible, usable, and even enjoyable.” It is envisioned as an amenity for a mixed-use, mixed-income neighborhood for 6,000 people that the public agency Waterfront Toronto intends to develop on former industrial land near the Don River. The most serious disadvantage Hume hinted at is the darkness of the area; that’s to be remedied by an elaborate array of LED and other artificial lighting.

When not to breathe

I hate to rain on these people’s parade, but it’s important to point out concerns that have been raised by public health researchers and advocates. Evidence is mounting that breathing the air near motorways is bad for you.

Environment & Human Health Inc. (EHHI), a North Haven, Connecticut, nonprofit organization dedicated to protecting human health from environmental harm, released The Harmful Effects of Vehicle Exhaust in 2006. The report tried to alert the public to dangers that, according to researchers, are more serious than many people recognize.

“Although we have all grown to accept the smell of engine exhaust as part of our everyday life, our nation is experiencing an epidemic of illnesses made worse by air pollution,” said the report’s lead author, Dr. John Wargo, professor of risk analysis and environmental policy at Yale University’s School of Forestry and Environmental Studies. “Some of the illnesses exacerbated by air pollution are asthma, cancer, diabetes, heart disease and respiratory illnesses.”

“Many of the chemicals in vehicle exhaust are carcinogenic,” Nancy Alderman, president of EHHI, emphasized when the report was released.

When I informed Alderman about Underpass Park and other public spaces being developed beneath highway structures, she replied, “There seems to be no end to really bad ideas. What are they thinking? The ... studies connecting vehicle exhaust to disease are too numerous to list.”

A 2006 study at UCLA found that people with asthma who live within 500 feet of busy streets or freeways are three times as likely to end up in the hospital as compared to asthmatics who live in low-traffic areas. Other studies have shown that the closer a freeway is, the higher the asthma rate.

Air pollution is a potent threat to children’s developing lungs. California, the Orange County Register reported, has had a law since 2003 prohibiting new schools within 500 feet of freeways.

If freeways are bad neighbors for schoolchildren, wouldn’t you think that under-the-freeway would be a questionable location for a park or recreation space?

Toronto’s decision

It occurred to me that perhaps the Toronto site might be acceptable if the traffic volume is minimal. So I checked with Robert Freedman, Toronto’s urban design director. Freedman said the overpasses — specifically, the Eastern Avenue and Richmond/Adelaide overpasses — don’t really carry highways. He characterized them as “part city street, part bridge, and part on-ramp.”

Rod McPhail, Toronto’s director of transportation planning, described the overpasses as “medium-volume streets with heavier peak period traffic flow.” Presumably they would generate less vehicle exhaust than a freeway. How much is unclear. Perhaps if the number of vehicles traveling those routes were checked against health hazard thresholds, a solid determination could be made about the wisdom of building a park there.

In any event, Toronto authorities appear not to have raised that kind of question. “I don’t think in the past we have looked closely enough at air quality in terms of all kinds of planning — whether for pedestrians on busy streets or creating cycling lanes,” Freedman acknowledged. “We need to get much more sophisticated about all of this.”

If public agencies were to make detailed assessments of pollution, including their effect on the more vulnerable parts of the populace, such as children, this could evolve into quite a complicated endeavor. There are so many variables. Are vehicles doing much idling? Starting and stopping?

“Driving behavior is also a factor,” emphasized Anstress Farwell, president of the New Haven Urban Design League. Farwell has frequently criticized road projects and proposed parking garages in New Haven when they seemed likely to burden neighborhoods with concentrated tailpipe emissions, aggravating an already high asthma rate. Places with a lot of braking and downshifting, Farwell said, “have pollution not only from vehicle exhaust but heavy particles from tires and brake lining that settle on sidewalks and accumulate in soils.”

If public agencies were to take all of that into account, it would raise nettlesome issues, especially in Toronto, where Rob Ford, upon becoming mayor last December, controversially declared, “Ladies and gentlemen, the war on the car stops today.”

“My hunch is that there are many parks adjacent to busier streets and highways across the city where the air quality is worse” than at Underpass Park, Freedman said. How that would be dealt with is unclear, but Freedman’s preference boils down to common sense: “I’d like to see emissions reduced — rather than parks eliminated.”

It’s a safe bet that across North America we’re going to see more development close to highways. Close-in, urban locations are becoming sought after, and there will be increasing pressure to use sites that were avoided in the past — like those that back up to busy roads. The time has come for transportation departments and city planners to familiarize themselves with the health issues.

The introduction to The Harmful Effects of Vehicle Exhaust states:

Over the past ten years, hundreds of studies have been published in the peer-reviewed literature demonstrating special vulnerability to air pollution among those with serious illnesses, including asthma, chronic obstructive pulmonary disease (COPD), cardiovascular disease, diabetes, and lung cancer. Tens of millions of Americans suffer from these illnesses. Children, the elderly, those with compromised immune systems, and those with specific genetic traits are at special risk. ...

During the past decade, scientists have also confirmed a relationship between two forms of pollution—ozone and particulate matter—and increased rates of mortality, especially among those with cardiovascular disease.

Those statements are five years old. Surely it’s past time to begin acting on them.