NYC TUNNEL:RPA urges 3-tube tunnel to replace Gowanus El
By Peter Samuel
The influential Regional Plan Association (RPA) in New York is pushing an 8-lane, 6km-long, c$2 billion, 3-tube highway tunnel, to replace the aging Gowanus Expressway opened 1941, a 6-lane elevated structure through Brooklyn, denoted I-278, that connects the Verrazano Narrows bridge and the Shore Belt Parkway at its southern end with the Brooklyn-Battery tunnel (to Manhattan) and the Brooklyn-Queens Exwy, at its northern end. The old Gowanus carries 150k vehs/day on 6-lanes with several sharp curves, short merge/diverge lanes and some steep grades, all of which are safety hazards and congestion-makers. The Exwy was built atop the posts of an abandoned BMT El (elevated) rail line on 3rd Av in Sunset Park and over Hamilton Avenue in South Brooklyn, pushed through against local protests by legendary NY road and bridge builder (and tunnel hater) Robert Moses.
Caros book on Moses says: The El had cast a shadow over 3rd Avenue, but the El had been 40ft wide. The Gowanus (expwy) was 94ft wide. And more than twice as dark. The gaps between the railroad ties had made the Els shadow a venetian-blind shadow; sunlight had come through as if through the slats of an opened blind. A highway was a concrete slab, without gaps. The construction of the Gowanus Expressway laying a concrete slab on top of lively bustling 3rd Av, buried the avenue in shadow, and when the roadway was completed, the avenue was cast forever into darkness and gloom and its bustle and life were forever gone.
Well for six decades but perhaps not forever!
This el-road monstrosity (from anywhere but up on it) dominates south-western Brooklyn and views of the magnificent New York Harbor with the Statue of Liberty, Ellis Island, and the lower Manhattan skyline. Its iron and concrete are deteriorating and indeed the thing has been periodically patched for several decades amid terrible disruption. It is overloaded for 6-lanes much of every day with 150k veh, a tedious mess only matched in this continent by our own Wilson Bridge on the Beltway (180k veh/day).
The unimaginative stodgy state and city engineers of New York government have an awful scheme to simply renovate the Gowanus el-road with minor ramp mods, which would cost $700m, disrupting traffic for 7 years 1999-2006, leaving capacity inadequate and the overhead eyesore in place indefinitely. It is such a dispiritedly defeatist or bone-headedly stupid idea that almost anything would be better. Some tunnel system is clearly superior, especially since there is road in trench at both ends.
RPAs Initial Feasibility Study A Gowanus Tunnel notes that the route is one of New York Citys most vital highway links and it pointedly rejects notions sometimes proposed by transit enthusiasts or architects that it be torn down and replaced by a surface road plus extra rail: The regional transportation need in the Gowanus corridor is for a road with interstate (motorway) capacity...the patterns of origins and destinations of the vehicles using the Gowanus show only a small proportion of trips begin and end near existing transit networks or any likely new elements of a transit network so the hope of reducing the need for highway transport capacity in the Gowanus corridor is not realistic. (FILE FOR REQUOTING)
As for getting truck cargoes onto rail, RPA says, studies have shown the maximum realistic diversion as 600 to 1,000 truck trips from the entire east-of-the-Hudson New York highway network so diversion from the Gowanus would be only a few percentage points of the 10,000-plus truck trips it carries.
RPA says bluntly that any solution short of the current motorway capacity will simply have through traffic diverting through local surface streets, so they recommend a lane-for-lane replacement involving two 3-lane tubes plus a big big bonus for transit of a central 2-lane tube for dedicated bus service. The proposed tunnel system would extend from 72nd St under the present Gowanus right of way 6km north to just west of Clinton St. There would be one intermediate interchange with four ramps coming underground at 39th St. However Prospect Exwy traffic that currently joins the elevated Gowanus would not join the G-tunnel but would join a rebuilt surface boulevard Hamilton Av atop the tunnel (and only join near the unchanged BBT/BQE IC. The Shore Belt Pkwy might be abandoned in its section between the 4th Av offramp immediately west of the Verrazano bridge and 3rd Av (the whole C-section around the shoreline of Bay Ridge), Shore Belt Pkwy through traffic joining the Gowanus in new direct ramps near the bottom of the Verrazano approaches around 92nd St before it went into tunnel.
The greater expense of an underground highway system is warranted, RPA says, because of the multiple benefits it provides to the communities it passes through, giving them back the sunlight and views and the avenue that the elevated Gowanus currently occupies. RPA sees the project as a possible model: The use of tunnels (goes) directly to some of the key urban problems New York faces: Opening up its waterfront, restoring the integrity of its neighborhoods, recreating land value, and building new roads that are impossible even to contemplate when just thinking about surface construction. Moreover urban tunneling would be less of a new innovation for New York than a return to one of New Yorks great traditions. In the first half of the 20th century New York City was a world leader in urban transport tunneling. Four road tunnels and over 20 subway and passenger rail tunnels under city waterways, not to mention all the miles of underground subway, are what make transport in the New York area possible. Finally tearing down an elevated facility and replacing it with underground faciliies is not a new course (either)...The question the Gowanus poses is: is it time to make New York a leader in urban tunneling here again? Right on!
Enviro threat to homeless: At a level of detail RPAs proposed 3/2/3 lane profile for the tunnel system is open to serious criticism two mixed-vehicle tubes of 3 lanes and a central dedicated bus tube of 2 lanes. The dedicated bus tube is a true gem of enviro/transit-nut indulgence given the tiny bus numbers on the Gowanus: average 274/day. Buses constitute less than two vehicles in every thousand on the Gowanus (0.18%) yet RPA would give them 25% of the proposed laneage, and indulge them with probably 30% of the capital cost of the project. And whereas the mixed vehicles lanes will carry about 30,000 persons/lane/day the bus lanes will, at most, carry 4,000 persons/lane/day. So much for the transit-boosters talk about bus-lanes and transit being efficient! This is like corporate CEOs who royally indulge themselves with their own special private elevator and personal bathroom facility so they wont have to risk chance encounters with mere employees. These rare Gowanus bus-riders, being politically correct icons of environmentalist virtue are to be indulged like latterday lords at the expense of the benighted unenlightened masses in their grubby automobiles! Such are the priveleges proposed to be bestowed on the righteous riders by priestly elders of the green church! Ah but cant we egalitarian-democrat insurgents invoke safety considerations to spike this nonsense? Given that the Gowanus bus tube will have a mere 137 buses/lane/day through it, this proposal is a mortal threat to the lives of the homeless. With bus headways of an average 10 minutes, a poor guy would have time to find a comfortable camping spot on the roadway, enjoy in leisurely sips a full hip-flask of whisky, reflect on the pleasantly benign climate of his deep-rock tunnel home, and fall into a life-threateningly deep sleep between one bus passage and the next! Advocates for the Homeless: Sue this heartless RPA!
Dubious sizing: Reference to a stock highway capacity manual will indicate that the proposed two-lane central tube will have sufficient capacity to carry the Gowanus 11,000 heavy trucks per day as well as that elite fleet of 274 buses! Which raises the question of why build the outer tubes with 3.6m lanes and 4.75m overhead, designed for heavy trucks? Just over 90% of the Gowanus traffic is light vehicles cars, sports-utilities, pickups and vans. Heck tunnels are expensive. Now, transport engineers and policymakers in France, and more important entrepreneurs like investor-owned tollster Cofiroute have spent the past ten years studying light vehicle tunnels as self-financing facilities and have fixed on a double-deck Metroroute profile of 3-lanes one direction on top of 3-lanes the other way with 2.55m (84) overhead and 2.9m (96) lane widths which can be accomodated within a single 10m (33) tube. Construction begins shortly near Versailles on the outer-ringroad A86-west boring 10km of such tunnel. And without a Franc of taxpayer money. Our light vehicles may be a bit bulkier than the French with more sports utility vehicles and larger vans so perhaps North American light vehicles need something like 2.9m (96) ceilings and 3.1m (102) wide lanes but those dimensions would fit six lanes (3-lanes double-decked) comfortably into a 13m tube doubling the capacity compared to the RPA scheme! Youd then need only one tube instead of the two 13m tubes proposed by RPA, huge savings ($700m?) that could make or break the project. There are other advantages in heavy/light vehicle segregation safety and driver comfort. Many car drivers hate driving alongside the freight behemoths! And when designing for light vehicles roadway grades can be steeper, curves tighter, super-elevation optimized and ramps shorter. In sizing all of our highway lanes to heavy truck dimensions we in the US are captive to a 1950s Pentagon-inspired requirement that the interstate system cater to military convoys, President Eisenhower having as a captain in world war one commanded an epic convoy through muddy tracks from San Francisco to New York, while seeing as general how the German army outflanked the French using their autobahns in 1940. At the height of the Cold War in launching the interstates there may have been some logic in the feds insisting that all highway lanes be built to heavy truck dimensions. But now? And in New York City? In expensive tunnels? These guys want to pander to the Pentagon and perpetuate Washington Waste!
Since New York City pioneered the beautiful car-only parkways in Westchester county (Sawmill, Bronx River, Hutch etc) and on Long Island, the RPA might draw on that rich heritage (and graciously acknowledge the recent French Metroroute innovations) to segregate heavy trucks and make its proposed urban road tunnels both more civilized and more affordable? Cool underground parkways! Separate truck tubes!
Tolls: The RPA paper does not touch either on the touchy subject of financing, which leaves a logical chasm still to be filled before this is a serious proposal. The freeing up of surface land by the eventual demolition of Brooklyns blighting el-road should provide some capital contribution to the cost of undergrounding the Gowanus. But it is hard to see how road facilities as inherently expensive as tunnels can be financed except by raising capital attracted by a prospective stream of toll revenues. And tolls varied by time of day or congestion-level will help manage the free-flow use of an expensive piece of infrastructure. Planning 6-lanes for 150k vehs/day, as the RPA does, seems horribly tight, especially if congestion pricing tolls arent being used to spread them more evenly through the day. But then guys who design a half billion $ bus tube for 274 buses/day obviously dont care that much for guys in cars, and they must believe in Washington DCs continued ability to deliver the mega-pork. Or support trendy transportation. This is a fascinating and creative proposal, worth watching and supporting in principle, but it will need many mods before its going to go anywhere. (Contacts Al Appleton, RPA 212 785 8000x371; Philippe Garnier, Cofiroute 33 1 4114 7378)