text: In the 1960s, Moses proposed straightening the West Side Highway, widening both the highway and the Henry Hudson Parkway, and constructing both the Lower Manhattan Expressway and the Mid-Manhattan Expressways, connecting routes that would have stretched across Manhattan. None of these projects were ever built. Later, in his 80s, he opposed the Westway project, but by that time his power was gone and his ideas generally weren't taken seriously. Rather than constructing a below-grade interstate highway, Moses proposed merely straightening and rebuilding the West Side Highway south of 59th Street. Between 59th and 72nd Streets, the site of the former Penn Central 60th Street rail yard, he proposed bringing the highway to grade and moving it eastward to allow for a waterfront park and some housing at the southeast corner of the rail yard.  This was the nucleus of the idea that led to the plan for Riverside South.
  1973 collapse
  The highway was obsolete almost from the beginning. Its lanes were considered too narrow and it could not accommodate trucks. Sharp "S" exit ramps proved hazardous, as did the left-hand exit and entrance lanes that made merging dangerous.
  On December 15, 1973, the northbound lanes between Little West 12th Street and Gansevoort Street collapsed under the weight of a dump truck, which was carrying over  of asphalt for ongoing repairs of the highway. A four-door sedan followed the truck through the hole; neither driver was seriously injured. The next day, both directions were 'indefinitely' closed south of 18th Street. This not only closed off the oldest section (between Canal Street and 18th Street), but also the newest sections (south of Canal Street), because ramps south of the collapse only permitted northbound entrances and southbound exits. The southernmost northbound exit was at 23rd Street.