Whilst googling the term “connectivity” I came across the “Livable New York” website with its resource manual (link). One of the chapters in the manual discusses “street connectivity.” What I found interesting is what appears to be a strong condemnation of the whole concept of road hierarchy. The author, Paul Beyer, writes:
After World War II (…) suburban communities were planned and built on a hierarchical system of roadways (….) The hierarchical system functioned (or not) like this: wide, local neighborhood roads connected isolated subdivisions (many dominated by cul-de-sacs and dead-ends) to a limited number of neighborhood collector streets; these collector streets delivered cars to minor and major arterials, usually at a limited number of access points; and these arterials then connected to freeways and highways.
This system reduced through-traffic, thus providing the privacy and isolation sought by families leaving the cities; and cul-de-sacs were seen as the safest environment for raising children. The downside was increased traffic congestion, decreased walkability/bikability, limited or no transit options, and complete reliance on the automobile.
But times are changing; many land use and transportation planning professionals are advocating for a more inter-connected street design system that promotes walking, biking, transit, slower car speeds, and greater quality-of-life.
OK, the article and source are not perhaps as authorative as a statement from a government Ministry, but it is at least a straw in the wind from someone else that “road hierarchy” might be a concept which has had its day.
699 – Beyer, Paul. “Street connectivity“, Livable New York Resource Manual, New York USA (downloaded June 2013)