Alarmed by a proliferation of cracks on the roadway decks of the Throgs Neck Bridge, the Metropolitan Transportation Authority intends to ban tractor-trailers and other heavy trucks during the day.
The bridge – which stretches from the Bronx to Queens and is the major commercial artery linking Long Island to Westchester County and upstate New York – is not believed to be in danger of collapsing.
But the cracks – in the steel deck structures on either side of the span – are ominous because they began appearing decades earlier than expected. One of the city’s newest bridges, the Throgs Neck opened in 1961. Traffic has grown by 72 percent since then, to 39.7 million vehicles in 2004 from 23.1 million in 1962.
An 80,000-pound weight limit has been on the books for years, but it was largely ignored until engineers concluded in April that cracks were multiplying at an alarming rate. The cracks were attributed to a surge in the number of six-axle tractor-trailers, which can weigh as much as 120,000 pounds when full. In the last five years, there has been a 113 percent increase in tractor-trailer crossings on the bridge.
After months of discussions with the trucking industry, the authority announced last week that it would begin strictly enforcing the weight limit today. Several trucking companies quickly filed a lawsuit, which called the crackdown “arbitrary and capricious” and argued that the authority should first be required to complete an environmental review.
The businesses assert that to comply with the weight limit, they would have divide their loads among many smaller trucks, worsening air pollution and traffic congestion. The other, longer alternative for trucks to and from Long Island is the often-congested Van Wyck Expressway and the Bronx-Whitestone Bridge.
On Thursday, in State Supreme Court in Manhattan, the authority agreed to temporarily refrain from issuing summonses or seizing heavy trucks, but officials said they would return to court to seek the right to do both immediately. Justice Paul G. Feinman has scheduled a hearing for Oct. 18.
Both sides agree that the efficient movement of goods and the integrity of the Throgs Neck Bridge are both critical for the regional economy. But there is no consensus on how to balance the two.
The Triborough Bridge and Tunnel Authority, a Metropolitan Transportation Authority subsidiary that manages nine bridges and tunnels, including the Throgs Neck, said that public safety demanded strict enforcement of the weight limit.
The decks, installed in the mid-1980’s in place of the original concrete decks, should have “a life expectancy in many decades,” so the appearance of cracks after only 20 years is disturbing, said Michael C. Ascher, the president of the bridge agency, also known as M.T.A. Bridges and Tunnels. Ignoring the cracks, he said, could have catastrophic consequences.
“While there may well be an economic impact by bringing the enforcement up to where it should be, the fact of the matter is a closure of a part or a whole of that crossing, the Throgs Neck Bridge, would have a devastating impact on the economy of Long Island and the region,” Mr. Ascher said on Thursday at a board meeting of the transportation agency.
The cracks were first identified in 1990 in the lightweight steel deck that supports the roadway on both approaches to the bridge. The 3,217-foot Queens viaduct and the 4,712-foot Bronx viaduct are each longer than the bridge itself, which is 2,910 feet from end to end.
Engineers tried to fix the cracks by drilling holes through the steel, distributing the stress that caused the crack around the hole. Even so, cracks continued to appear.
“There is no imminent danger, and these cracks are being carefully monitored,” said Thomas Bach, the chief engineer at the bridge agency. “We are analyzing repair methods. The purpose of what we’re doing here is to prevent the damage from continuing and getting worse.”
The authority has agreed to allow trucks up to 89,000 pounds – slightly higher than the weight limit – on the bridge’s two center lanes, the strongest of the six traffic lanes. Under the proposed crackdown, trucks heavier than that may cross the bridge only from 11 p.m. to 5 a.m., and with an escort who will ensure that they are driven slowly, to minimize stress on the bridge. Other traffic would be restricted during such crossings.
Enforcement of the weight limits would be particularly devastating to companies that move aggregate, the crushed stone used to make asphalt and concrete, according to industry representatives. They said the higher costs of moving the materials would be passed on to contractors and consumers.
“You would have to double the number of trucks in the business if you had to operate at that 89,000-pound limit,” said Francis X. McArdle, managing director of the General Contractors Association of New York. It would be more cost-effective to rebuild the deck “so it can carry what needs to be carried, as quickly as possible,” he said.
Robert F. Carlino, executive director of the Long Island Contractors Association, said that building materials usually cannot be delivered at night because of noise and traffic restrictions.
Opponents of the weight limit said that the authority had provided no evidence to support its analysis. “There’s no one looking over the engineers’ shoulders,” said John T. Cooney Jr., president of Tilcon New York, a unit of CRH, a big Irish building-materials company. “They’ve made this decision in a windowless room.”
The lawsuit contends that the authority has long accepted the state’s so-called divisible-load permits, which allow maximum weights of 120,000 pounds. The authority notes that the permits are not valid in the city.
One of the plaintiffs in the suit, Emilio Lamanna, the president of Almar Supplies of Maspeth, Queens, said he was particularly upset by the sudden nature of the decision. “We’re willing to follow the rules,” he said. “Give us a time frame so that we can slowly adjust to this.”