The construction of the Brooklyn Queens Expressway in the mid-20th century was one of New York City über-planner Robert Moses’s proudest triumphs. The destruction the BQE subsequently brought to neighborhoods along the Brooklyn waterfront is today considered one of Moses's most reviled legacies. Moses dug a trench through Red Hook to carry his dream road, gutting a thriving immigrant community. Traffic roars along there still, exhaust pouring out of the ditch where the highway runs.
Farther north, the more affluent residents of Brooklyn Heights were able to prevent Moses from tearing up their neighborhood’s historic brownstones, which now routinely sell for millions of dollars. The BQE here clings to the bluff that gives the Heights their name, running under a pedestrian promenade that offers spectacular views of Manhattan.
When Moses built the BQE, no one worried about the impact of the road on what was then industrial waterfront directly below the Brooklyn Heights Promenade. But today, those working piers have been reinvented as Brooklyn Bridge Park. Stretching for 1.3 miles along the harbor, the park — which is being constructed one segment at a time over the course of several years — has quickly become one of the borough’s most popular outdoor destinations. Designed by landscape architect Michael Van Valkenburgh, it has brought much-needed recreation areas to a part of the city where large open spaces are in short supply. But its success means that the grinding din of the nearby BQE, quite audible in some parts of the park, has become an affliction for yet another generation of New Yorkers.
A new section of the park just opened, and it features an ingenious solution to the looming problem of Moses’s legacy. A 30-foot-high earthen berm blocks the pedestrian path and lawns from the BQE, shielding park users from the view of the roadway. More importantly, it cuts the irritating, stressful sound of the cars and trucks motoring along. Walking along the path and passing from the section unprotected by the wall to the place where it begins is the auditory equivalent of entering into cool shade after being exposed to the glaring sun.
How significant is the difference? On the relatively low-traffic morning of the day after Christmas, I used a decibel-meter app on my phone to measure the effect. Keep in mind that the ambient noise from the harbor is relatively high, with intermittent but frequent boat and helicopter traffic. Keep in mind also that the decibel scale is logarithmic, and that 80 decibels represents 10 times the intensity of 70 decibels. (The system is actually incredibly complex. if you want to dive in you can start here or here). And obviously, the app is not a professionally calibrated sound-measuring instrument.
On the unprotected pathway, the average reading hovered in the low- to mid-80s, a level described by the sound engineers at Industrial Noise Control as being equivalent to an average factory, or a freight train at a distance of about 15 yards. Eight hours of exposure to levels like that can result in hearing damage. Once I passed into the "sound shadow" of the berm, the average reading went down to about 69, closer to the level of a lively conversation. The relief I felt was palpable. Suddenly, I realized I could hear the waves lapping at the shoreline.
The long-term health effects of noise in modern cities are only beginning to be understood, although anyone who has ever lived in a city knows intuitively how stressful the constant din of motorized traffic can be. The new wall at Brooklyn Bridge Park provides a bit of respite from the assault. But it’s only a few hundred feet long. Its greater value may be in the way it makes us aware of the destructive and unpleasant sonic reality we take for granted every day.