BROOKLYN NY $18m for Gowanus tunnel study
By Peter Samuel
$18m for Gowanus tunnel study
The new federal highway bill provides $18m for comprehensive studies of putting the Gowanus Expressway underground through Brooklyn NY. The Gowanus is an aging 1940s 6-lane elevated highway (built on the superstructure of an abandoned el or elevated rail-line mostly over 3rd Av) that links the Verrazano Narrows bridge to the Brooklyn-Queens Expwy and the Brooklyn-Battery Tunnel. It is an interstate route, I-278, that connects Long Island and the eastern boroughs of New York City with Staten Island and, via the Goethals toll bridge, to NJ, PA and the west.
6km in length and designed for perhaps 200k veh/day the Gowanus Underground would be the most ambitious tunnel highway project in the US after the Central Artery in Boston.
NY State DOT regards the underground project as an extravagence and has proposed to renovate the existing elevated highway for about $700m but there is strong opposition to this. The elevated casts a blight over a long section of Brooklyn, and the reconstruction of the existing structure would produce years of choked and diverted traffic. Many of the opponents of the elevated rehab support the tunnel proposal which is being pushed by the influential Regional Plan Association.
RPA has garnered the support of local politicians for the funding of full studies of the options. Al Appleton there told us he hopes there will be full engineering, cost and feasibility studies of alternative profiles of the tunnel including examination of the French MetroRoute concept of segregating smaller vehicles (they have set 2.0m as a height limit) from heavy trucks and buses (see TRnl#26 Apr98 p13). The concentration of the majority small vehicles in narrower low clearance lanes markedly reduces the tunnel cross-section and cost, Appleton notes, as compared to sizing underground lanes entirely for minority large vehicles, but he says he has an open mind on that issue. Before the concept was accepted, major political, regulatory and safety obstacles would have to be overcome.
The Gowanus undergound highway might consist of 6-lanes for light vehicles and two lanes for heavy, the kind of split envisaged for the A86-W tunnels in France, though the small vehicles tube planned there is nearly twice as long (10km vs 6km.) In Paris the less profitable large vehicles tube is being deferred until some time after the small vehicles tunnel is complete. That project relies entirely on investor capital. It is likely more generous dimensions would be needed for US light vehicles which include so many large vans and sport utility vehicles 1.8m high. In France the vast majority are 1.4m to 1.6m high cars.
After the Gowanus the adjacent elevated Brooklyn-Queens Exwy to its immediate north is another possible candidate for replacement with an underground highway, a further ten years off probably. It is unclear at what stage the issue of funding would be addressed, but these two facilities have toll crossings at each of their endpoints. (Verrazano, Brooklyn-Battery, Triboro), and tolling would be an attractive source of funding as well as a potent means for managing traffic flows. Money for the studies got unanimous support from the New York delegation. (see TRnl#17 Jul97 p10, contact Al Appleton RPA 212 253 2727x371)