Brooklyn Bridge - Pedestrian and Vehicular Access

Pedestrian and Vehicular Access

At various times, the bridge has carried horse-drawn and trolley traffic; at present, it has six lanes for motor vehicles, with a separate walkway along the centerline for pedestrians and bicycles. Due to the roadway's height (11 ft (3.4 m) posted) and weight (6,000 lb (2,700 kg) posted) restrictions, commercial vehicles and buses are prohibited from using this bridge. The two inside traffic lanes once carried elevated trains of the BMT from Brooklyn points to a terminal at Park Row via Sands Street. Streetcars ran on what are now the two center lanes (shared with other traffic) until the elevated lines stopped using the bridge in 1944, when they moved to the protected center tracks. In 1950 the streetcars also stopped running, and the bridge was rebuilt to carry six lanes of automobile traffic.

The Brooklyn Bridge is accessible from the Brooklyn entrances of Tillary/Adams Streets, Sands/Pearl Streets, and Exit 28B of the eastbound Brooklyn-Queens Expressway. In Manhattan, motor cars can enter from either direction of the FDR Drive, Park Row, Chambers/Centre Streets, and Pearl/Frankfort Streets. Pedestrian access to the bridge from the Brooklyn side is from either Tillary/Adams Streets (in between the auto entrance/exit), or a staircase on Prospect St. between Cadman Plaza East and West. In Manhattan, the pedestrian walkway is accessible from the end of Centre Street, or through the unpaid south staircase of Brooklyn Bridge-City Hall IRT subway station.

The Brooklyn Bridge has a wide pedestrian walkway open to walkers and cyclists, in the center of the bridge and higher than the automobile lanes. More than 4,000 pedestrians and 3,100 cyclists cross the Brooklyn Bridge each day. While the bridge has always permitted the passage of pedestrians across its span, its role in allowing thousands to cross takes on a special importance in times of difficulty when usual means of crossing the East River have become unavailable.

During transit strikes by the Transport Workers Union in 1980 and 2005, the bridge was used by people commuting to work, with Mayors Koch and Bloomberg crossing the bridge as a gesture to the affected public.

Following the 1965, 1977 and 2003 blackouts and most famously after the September 11, 2001, attacks on the World Trade Center, the bridge was used by people leaving Manhattan after subway service was suspended. The massive numbers of people on the bridge could not have been anticipated by the original designer, yet John Roebling designed it with three separate systems managing even unanticipated structural stresses. The bridge has a suspension system, a diagonal stay system, and a stiffening truss. "Roebling himself famously said if anything happens to one of systems, 'The bridge may sag, but it will not fall.'" The movement of large numbers of people on a bridge creates pedestrian oscillations or "sway" as the crowd lifts one foot after another, some falling inevitably in synchronized cadences. The natural sway motion of people walking causes small sideways oscillations in a bridge, which in turn cause people on the bridge to sway in step, increasing the amplitude of the bridge oscillations and continually reinforcing the effect. High-density traffic of this nature causes a bridge to appear to move erratically or "to wobble" as happened at opening of the London Millennium Footbridge in 2000.