This week’s topic of Weis and Arnesen’s “Thriving as a City in 2020” is a continuation of effective transportation, this time focusing on street layouts.
The Not-So-Distant Future: Cities in 2020, Part 6
Posted By Megan Wildhood
Oct 30, 2012
Weis and Arnesen continuing their discussion of effective transportation from last week, this time arguing against the current most common design scheme for streets – the crisscrossing grid of largely two-way streets with stoplights nearly every block. The authors not only explain why this is inefficient (and thus unsustainable), but explain a feet-first-friendly alternative:
STREET GRIDS FROM 1890: A CASE OF TOO MANY LIGHTS
Our current pattern of street grids and traffic lights is a century old – and a half-century obsolete. There is simply no contemporary justification for our city centers still being patchwork grids of crisscrossing streets with traffic lights. This century-old pattern does not move traffic efficiently, it impedes pedestrian movement, and it certainly does not add to the urban atmosphere. Replacing this relic with modern street ovals for through traffic, circling inner cores of pedestrian commercial zones, is a step that is at least four decades overdue. Parking, discussed in the next section, should be accessible from these traffic ovals and placed underground toward the commercial pedestrian zones that the traffic oval surrounds.
Let’s begin with the proposition that 80 percent of the street lights in service in most American city centers can be and should be eliminated. The central commercial core of a city should be a pedestrian zone, thereby eliminating all of the traffic lights previously in use in this multi-block zone – probably ranging from between 10 and 20 city blocks in most urban centers. A 20-square-block pedestrian zone would obviate the need for 30 traffic lights.
The street “oval” referred to above is a one-way through street circumnavigating the pedestrian zone, configured to move vehicular traffic around the outer perimeter of the pedestrian zone, and into parking spaces that serve this commercial zone, ideally underground lots that feed vehicle occupants directly into the pedestrian zone above. For example, if the street oval were moving traffic clockwise around the pedestrian zone, the parking lot entrances and exits would logically be on the right side of the street, adjacent to the pedestrian zone. The street oval would be a thoroughfare, without traffic lights to impede the continuous flow of traffic into and out of the central parking areas. Fanning away from the central oval would a contiguous system of one-way through streets, thereby limiting the need for, and use of, most traffic lights to control the flow of vehicle traffic.
Despite this modernized and streamlined design for traffic flow into and out of the city core, most access to the commercial pedestrian zone would be via public transportation systems that flow under the central zone. In a future of energy shortages and global warming, there is no viable substitute for public transit as the primary mode of transportation (Revkin, 2007).
What Weis and Arnesen argue for – a pedestrian-centered city core unhindered by streets they must wait to cross with rings of one-way roads for public and personal transportation radiating outward, unhindered by stoplights – is long overdue. Perhaps one of this reasons it is so long in coming is that, for the past several decades, the “handbook” for street and highway design – called the “Green Book” – was compiled by a collection of lobbyists for highway spending and has only slowly expanded to include other areas of transportation concerns, like designing places for people walking, biking and creating urban green space.
Cities also have a lot of liability and legal issues on all levels, but particularly the state, to overcome, evaluation routines to revamp and current standards to debunk. Cities in California provide an example of many of the difficulties cities will face in redesigning and modernizing their transportation structures, but what Weis and Arnesen suggest isn’t, according to them, an option. Energy shortages and climate change make transportation efficiency, which make walkable cities important for all cities everywhere.