[image] [image] A cul-de-sac (originally in anatomy: French, literally "bottom of a sack") or dead-end street is a street with only one inlet/outlet. A cul-de-sac is usually differentiated by having a turnaround area at its closed end.
In modern Urban planning cul-de-sacs are deliberately created to limit through-traffic in residential areas. While some cul-de-sacs provide no possible passage, others allow cyclists, pedestrians or other non-automotive traffic to pass.
This is in contrast to early 20th century American Urban planning which emphasized a grid layout, partially out of wide reliance on streetcars, and alleys.
The use of cul-de-sacs reduces the amount of car traffic on residential streets within the subdivision, thus reducing noise and the potential for accidents. It also essentially eliminates non-motorized traffic and most through-traffic. This is, in turn, thought to decrease crime and increase desirability, because very few people enter the neighborhood who do not live there, or are the guests of people who do. It also facilitates gated communities, because of the small number of entrances.
More generally, the New Urbanism movement has offered criticism of the cul-de-sac and other streets not intended to network with each other. It has been suggested that such street layouts can cause increased traffic on the non-cul-de-sac streets, make navigation (especially on foot) inconvenient and non-intuitive, and reduce the size of any given neighborhood to a single street.
This applies especially to back-to-front housing where the front of the house fronts onto the cul-de-sac lane while the rear fronts onto the main roads. The Macquarie Fields riots of 2005 were a result of this kind of urban design.