Street hierarchy: Difference between revisions

Revision as of 21:56, 24 October 2023

Revision as of 01:22, 10 January 2024

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{{Short description|Urban planning restricting through traffic of automobiles}}

{{Original research|date=October 2023|reason=Several paragraphs contain unsourced information on a niche subject.}}

{{more citations needed|date=July 2019}}

{{Short description|Urban planning restricting through traffic of automobiles}}

[[File:Radburn Cellular Street Pattern.jpg|thumb|300px|right|The network structure of [[Radburn, New Jersey]] exemplifies the concept of street hierarchy of contemporary districts. (The shaded area was not built.)]]

The '''street hierarchy''' is an [[urban planning]] technique for laying out road networks that exclude automobile through-traffic from developed areas. It is conceived as a [[hierarchy of roads]] that embeds the link importance of each road type in the [[network topology]] (the connectivity of the nodes to each other). Street hierarchy restricts or eliminates direct connections between certain types of links, for example residential streets and [[arterial road]]s, and allows connections between similar order streets (e.g. arterial to arterial) or between street types that are separated by one level in the hierarchy (e.g. arterial to highway and collector to arterial.). By contrast, in many regular, traditional [[grid plan]]s, as laid out, higher order roads (e.g. arterials) are connected by through streets of both lower order levels (e.g. local and collector.). An ordering of roads and their classification can include several levels and finer distinctions as, for example, major and minor arterials or collectors.

At the lowest level of the hierarchy, [[cul-de-sac]] streets,<ref>[https://www.oregon.gov/lcd/Publications/NeighborhoodStreetDesign_2000.pdf] An Oregon Guide for Reducing Street Widths | Neighborhood Street Design Guidelines</ref> by definition non-connecting, link with the next order street, a primary or secondary "collector"—either a ring road that surrounds a neighbourhood, or a curvilinear "front-to-back" path—which in turn links with the arterial. Arterials then link with the intercity highways at strictly specified intervals at intersections that are either signalized or grade separated.

, by definition non-connecting, link with the next order street, a primary or secondary "collector"—either a ring road that surrounds a neighbourhood, or a curvilinear "front-to-back" path—which in turn links with the arterial. Arterials then link with the intercity highways at strictly specified intervals at intersections that are either signalized or grade separated.

In places where grid networks were laid out in the pre-automotive 19th century, such as in the [[American Midwest]], larger subdivisions have adopted a partial hierarchy, with two to five entrances off one or two main roads (arterials) thus limiting the links between them and, consequently, traffic through the neighbourhood.