Suburban Nation - Andres Duany [81]
The standard practice: a street of single-family houses in a nearby subdivision
As one leaves the center and approaches the neighborhood edge, building densities decrease and there occurs a corresponding shift in the design of the street. Every single aspect of the public realm transforms from urban to rural. Closed curbs and gutters become open swales; trees stop lining up and become more varied in species; sidewalks narrow and eventually disappear; and front yards become gradually deeper. In this way, there is an authentic and gentle transition from culture to nature. This sort of detailing, which is essential to giving a neighborhood a unique sense of place, requires designers and developers to exercise a degree of care that is now rare. One can only hope that the financial success of the new places designed in this manner will eventually encourage more developers to invest in such precise design.
An inverted city: the plan of Markharn, Ontario, with a central core of sprawl surrounded by subsequent layers of traditional street network (Cornell is at the extreme right)
From most rural to most urban: street frontages vary in response to their location within the neighborhood
The gradual transition from center to edge occurs most clearly in villages, which by definition are single neighborhoods sitting free in the landscape. In towns or cities, where multiple neighborhoods meet across shared main streets, the neighborhood edges may instead be designed as areas of increased density and activity. In this case, the urban/rural transition is reserved for the outer edge of the entire collection of neighborhoods.
A typical Cornell neighborhood: a main street at one edge, a school at another, a commercial central square, and a playground in each quarter
In addition to this radial organization, the neighborhood also possesses a Cartesian substructure, as shown at left. The larger streets that lead to the center divide the neighborhood into quadrants, each of which is sized to be the independent realm of the small child. As such, each is equipped with nothing but the slowest roads, and contains a local “pocket park”—often no bigger than a single house lot—located within a three-minute walk of every dwelling. The neighborhood thus grants freedom of motion and a certain degree of autonomy even to its youngest citizens.
MAKING TRANSIT WORK
The neighborhood structure is naturally suited for public transit, be it light rail, trolleys, buses, or jitneys. But there are also three rules that transit must follow in order to appeal to users, regardless of the urban framework:
1. Transit must be frequent and predictable. The challenge is not to prove this obvious principle but to create a transit system in which frequency is economically viable. This objective can be achieved only at certain densities; studies suggest that a minimum of seven units per acre is necessary if transit is to be self-supporting.dd For lower densities, the careful organization of neighborhood centers, to be served by smaller vehicles, can result in a successful network. This network, however, would likely require financial support.
2. Transit must follow a route that is direct and logical. Riders shy away from transit systems in which the path is not efficient and easy to understand conceptually Anyone who has ever taken a shared hotel bus to the airport knows how intolerable an uncertain, zigzagging route can be. Yet bus routes often dogleg interminably. The desire for a trustworthy, unchanging route is one factor that helps explain riders’ preference for light rail