At L.I. Overpass, New Rules Are Announced for Truckers Tractor-trailers and other commercial vehicles are prohibited from using parkways in New York, like the Jackie Robinson Parkway in Brooklyn and Queens and the Saw Mill River Parkway in Westchester County. But inadequate GPS units sometimes lead truck drivers astray and onto these roads, causing accidents when trucks cannot fit beneath bridges - a problem that has persisted for years despite advances in technology. On Monday, Senator Charles E. Schumer and federal officials announced new federal standards for GPS technology in the trucking industry at a news conference at the Eagle Avenue overpass of Long Island's Southern State Parkway. The bridge has been struck at least 27 times by trucks that should not have been on the road, Mr. Schumer said. "Eighty percent of all the trucks that get stuck under bridges are a result of using the wrong GPS," Mr. Schumer said in a phone interview. Last year, there were 58 reported bridge strikes in New York City, according to the city's Transportation Department. The federal Motor Carrier Safety Administration will now issue official recommendations for GPS systems approved for use in commercial trucks. The professional-level devices take a vehicle's height, weight and contents into account and direct drivers away from prohibited roads, while consumer devices do not have that capability, Mr. Schumer said. The professional devices are more expensive, he acknowledged, but they will save truckers and taxpayers money in the long run by preventing damage to vehicles and infrastructure and by preventing traffic jams. People renewing or applying for commercial driver's licenses will also be required to take GPS training, Mr. Schumer said. A 2011 report by the State Department of Transportation found that the most common city locations for over-height truck accidents included the F.D.R. Drive, which accounted for 87 percent of those incidents in Manhattan; the Belt Parkway, the site of 70 percent of Brooklyn's total; and the Hutchinson River Parkway, where 60 percent of such Bronx collisions occurred. The Westchester Avenue overpass of the Hutchinson River Parkway and the F.D.R."s junction with the Gracie Mansion Tunnel at 88th Street are particularly notorious stretches, the report said. The problem also extends to the Hudson Valley, where 855 over-height truck accidents occurred from 1993 to 2011, and Long Island, which had 341 such accidents over the same period. "In the Northeast, we're particularly susceptible to this because many of the highways were built before trucks were a main mode of transportation," Mr. Schumer said. Many of them were built for recreational purposes, by Robert Moses and others.