Suburban Nation - Andres Duany [33]
The misplaced priorities of current traffic engineering criteria are plainly evident in the top image on page 72, taken from the cover of a D.O.T. annual report—a photograph, therefore, that one can presume represents traffic design at its best. What this photograph depicts is indeed an achievement of sorts: a road of only four lanes that, thanks to highway geometrics, has managed to eat up over 150 feet in right-of-way width while lowering the property value of everything around it. Due to the behavior of the vehicles on this high-speed road, this area will always be the site of the cheapest housing and least prestigious businesses, hiding behind their walls, berms, and sound-attenuation barriers.
The street as automotive sewer: streamform highway geometries sever walking connections and preclude pedestrian life
To fully grasp this wastefulness, we need only consult the alternative: the traditional boulevard. Instead of an intimidating fourlaner, this boulevard is a twelve-laner: six lanes of traffic and six of parking. Yet this roadway is so charming and comfortable, thanks to its avoidance of high-speed geometries, that residents pay good money to sip coffee at curbside cafés—a sight hard to imagine in the preceding photo. The impact of the dumbing down of the engineering manuals could hardly have been more profound. In the early twentieth century, practically every roadway investment resulted in an increase in the value of adjacent properties. But since 1950, roadway investment has often had the opposite effect, robbing neighborhoods of their economic value by degrading the environment.
The street as a complex, multipurpose social organism: a boulevard, ideal for driving, parking, walking, and sipping coffee
The engineers’ strict adherence to their manuals is actually promising; rather than convincing the engineers to fundamentally rethink their approach, we need only amend the manuals in order to reform the profession. And to their credit, a coalition of forwardthinking engineers is on its way to making this happen. The Institute of Transportation Engineers has recently completed a manual entitled Traditional Neighborhood Development Street Design Guidelines, which allows narrower roads, tighter corners, and a number of other once-unthinkable modifications to current design criteria. For the moment, these modified standards are available only as optional alternatives.ao Clearly, the next step would be to prohibit the conventional high-speed standards in residential neighborhoods, restricting them to long-distance regional roadways, where they belong.
After speeding automobiles, the greatest threat to pedestrian safety is crime, which is what most people have in mind when they clamor for safer streets. It has been the topic of many design books, and the reigning classic remains Defensible Space, by Oscar Newman. It is worth elaborating on one of Mr. Newman’s subjects as it pertains to suburbia, and that is the concept of “eyes on the street,” a phrase originally coined by Jane Jacobs.ap
In order to discourage crime, a street space must be watched over by buildings with doors and windows facing it. Walls, fences, and padlocks are all less effective at deterring crime than a simple lit window. Interestingly, no one needs to be standing in the window, as the window implies a human presence on its own—at any moment, someone could appear. So it is really the windows, not the occupants, that are the eyes on the street. Traditional urbanism excels at providing them, as buildings sit close to the sidewalk and plainly face forward. Even residential alleys can be well supervised, by placing granny flats above garages.
Conventional suburbia fails to provide adequate street supervision. Most collector roads aren’t fronted by buildings at all. Houses tend to be located far from the street, sometimes behind walls. And, within typical subdivisions, houses often present