 First, because many of these roads were either designed before civil engineers had experience building roads for automobile use or widened in response to increasing traffic, many New York parkways lack shoulders.Second, because designers focused more on making routes scenic rather than efficient, the parkways are meandering, often built to follow a river, and so contain many turns.Finally, because most use low, decorative stone-arch overpasses that would trap trucks, commercial vehicles, trucks and tractor trailers are banned from parkways.