In 1982, Griesa blocked the construction of Westway, a proposed six-lane highway on the West Side of Manhattan, ruling that the permit for the project's landfill was invalid because the U.S. Army Corps of Engineers had failed to comply with the requirements for an adequate statement on the environmental impact. Although his decision dismissed various other attacks that environmental groups were using to stop the project in a series of lawsuits, he left one critical issue and said that the road might harm striped bass. His order was unanimously affirmed by a three-judge panel of the U.S. Court of Appeals for the Second Circuit. In 1985, after the Army Corps of Engineers completed another environmental review, Griesa again faulted their methods and record keeping, voided their permit and continued his injunction against the construction of Westway. His decision was again upheld by the Court of Appeals for the Second Circuit. Westway was never built.
