When these photographs were taken, the Williamsburg Bridge was undergoing major reconstruction. At different points, the pedestrian-bicycle path was either above, below, or adjacent to the roadway.

The following photographs and decibel readings compare the noise levels that resulted from each configuration.

Observations: The noise level below the roadway is 9.9 dBA less than the noise level beside the roadway because the path below the roadway isn't directly exposed to traffic noise. (Subjectively, this means that the noise below the roadway is half as loud as the noise beside the roadway.)

The noise level above the roadway is only 3.4 dBA less than the level beside the roadway (there are lanes to the side of the elevated path, so it is partially exposed to the noise below). Areas above the roadway are exposed to noise from passing subway trains as well.

While the noise level is best below the roadway, losing the dramatic views of Brooklyn and Manhattan is a hefty price to pay. Likely, the best design in terms of amenity for pedestrians and cyclists is to place the pathway above a fully-covered roadway. The traffic noise at the East River Promenade at 84th Street in Manhattan—which is located above a covered highway—is barely audible.