In 1969, the secretary of transportation approved a plan to extend an interstate highway through Overton Park in Memphis, Tennessee. A group of environmentalists petitioned the courts, seeking to enjoin the Department of Transportation (DOT) from financing the project. They argued that under the Federal Aid Highway Act, federal funds could not be used for highway construction through a public park if a "feasible and prudent alternative" existed. DOT personnel produced affidavits indicating that the secretary had considered other alternatives and argued that, unless there was substantial evidence to the contrary, the secretary's decision should be upheld by the reviewing court. Who won this case and why?