Monthly Archives: December 2006

Connectivity Part 2: Historical Background

This is part 2 of a series. See also IntroductionLatter Half of the 20th CenturyNeighborhood WalkingNeighborhood CrimeVehicle Miles and TrafficCrash Safety

Before the automobile age, people didn’t think much about connectivity. It was taken for granted that well-connected street networks were the best way to build cities. The routes between buildings had to be as convenient as possible because everyone moved slowly, compared to today’s motorized transport. Most city folk traveled at 2-4 mph (the speed of walking) and even those with vehicles didn’t move much faster than 7-9 mph (the speed of a horse and buggy).

The invention of the automobile changed all that and gushers of oil provided the fuel. Growth of vehicle production was explosive. America went from 8,000 vehicles in 1900 to 9.2 million in 1920 and 23 million in 1930. In 1916, military trucks allowed the French to win the battle of Verdun. It was the first time motorized vehicles were decisive in a large battle. World War I was pivotal in motorizing the U.S. military.

Some architects and planners believed they could transmute the power of mass motor vehicle use into a force for good: a force to alleviate poverty, squalor and oppression of the masses. European modernists like Charles-Edouard “Le Corbusier” Jeanneret and Ludwig Hilberseimer were revolutionaries, fascinated with large-scale schemes that would wipe away the old order and comprehensively reorganize cities for personal mobility via the automobile. The selling points were speed, efficiency, cleanliness and progress, a message that played especially well in America.

Ludwig Hilberseimer, Hochhausstadt, 1924

The American regionalism movement denounced overcrowded, unhealthy cities and the growing threat posed by automobile collisions. As mass ownership of cars and trucks became a reality in the 1920s, the regionalists along with their allies in government, and eventually the real estate industry, began to rethink thoroughfare patterns. Here was something new, they reasoned: door to door service at 30 mph or better! Gradually they concluded that all the old assumptions about connectivity could be tossed aside. Drawing on the Garden City tradition, their solution was a universal pattern of low density cul de sacs set in superblocks.

These initiatives were blows to connected streets in multiple ways. Disconnected street networks became the default pattern throughout the second half of the twentieth century.

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To New Horizons

The 23-minute film To New Horizons is a documentary of the 1939 World’s Fair “Futurama” exhibit. The film and exhibit were commissioned by General Motors to promote a cultural and spatial re-organization of American society that would maximize the corporation’s sales for decades to come.

The opening sequence, filmed in black and white, is a paean to Progress (with particular attention to the field of highway engineering). Then at minute 7:50, the film switches to Technicolor and begins a tour of the Futurama exhibit — a vision of the futuristic world of 1960. Throughout the film, narration is intoned in a reverent, quasi-religious manner backed by portentous skating-rink theremin music.


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The Market for Mixed Use & Walkability

There’s a lot of confusion and skepticism about what Americans really want in a neighborhood. The conventional “American Dream” has, for more than a century, been an house with an acre or so of land in the idyllic suburbs. A lot of Americans still desire that dream — but what percentage, and under what conditions? And will the majority want that dream in the future, or are cultural shifts in the offing? Let’s look at some surveys and projections about the market for neighborhood types.

Current Demand

Several surveys of market preferences have found that a solid majority want large, detached homes, while at the same time there is substantial support for walkability and proximity to mixed use. A 2002 National Association of Homebuilders survey found that a majority wants big, low-cost, spread-out houses, but also that 25 to 35 percent wants destinations within walking distance, sidewalks, workplaces closer to home, and infill in the center city or inner suburbs.

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Macdonald on Street Trees and Intersection Safety

Street trees: valuable neighborhood amenity or safety menace? Many traffic engineers and municipalities take a dim view of arboreal canopies near corners. Now, offering a more positive view, comes Street Trees and Intersection Safety by Elizabeth Macdonald et al. It is probably the most complete investigation of this topic to date, and is nicely readable (for an academic study, that is). Here is some of the opening paragraph:

The study derives from a rather simple, straightforward observation: that on the best tree-lined streets the trees come close to the corners. They do not stop at some distance back from the intersecting street right-of-way. Indeed, in Paris, a city noted for its street trees, if the regular spacing of trees along the street runs short at an intersection, there is likely to be an extra tree placed at the corner. For at least 250 years, the finest of streets the world over have been associated with trees. (p. 7)

The study looks at regulations that have the effect of prohibiting trees on corners, or of stripping street corners bare. Often these regulations are ad hoc and discretionary:

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Connectivity Part 1: Introduction

This is part one of a series. See also Historical BackgroundLatter Half of the 20th CenturyNeighborhood WalkingNeighborhood CrimeVehicle Miles and TrafficCrash Safety

Thoroughfare network connectivity is the single most important element of sustainably-built cities and towns. That may sound like an odd statement, particularly if you’ve never even heard of it. Connectivity has so many interrelated effects on so many urban functions, and more people should recognize how truly essential it is.

Why is connectivity so important? There are many steps to trace, so in this post I’ll start with a definition and overview.

The thoroughfare network is simply the system of arterials, collectors, boulevards, avenues, streets, roads, etc., in an area. Connectivity refers to the directness of travel routes between any two locations, and the number of alternative routes available for traveling between any two locations.

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Is Your NU Too New?

A column by Steven Pearlstein today’s Washington Post business section complains about Reston Town Center. Yes, it’s well designed. Yes, it achieves density without sacrificing the human scale. Yes, it has attracted big-name tenants, and yes, it’s a great financial success. But it’s just “too neat, too homogenized.” It has no liquor stores, no bums or graffiti. It lacks “messy vitality.”

Tysons Corner, says Pearlstein, is more dynamic and real. Yes, it’s one big traffic jam after another. Yes, it’s ugly. But it has “variety, ordered chaos and an urban-like intensity that puts you on edge.” In Mr. Pearlstein’s opinion, it’s a lot like Chicago, Manhattan and San Francisco that way.

Um, I’ve never noticed any bums or graffiti in Tysons Corner either. The only thing dynamic about Tysons’ civic realm is the masses of automobiles gunning from stoplight to stoplight. I agree, it certainly does put you on edge.

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