This is part 7 of a series. See also Introduction • Historical Background • Latter Half of the 20th Century • Neighborhood Walking • Neighborhood Crime • Vehicle Miles and Traffic

High-connectivity thoroughfare patterns are the foundation of walkable neighborhoods and districts. While that fact was self-evident for most of human history, it was lost or ignored by land development and transportation professionals in the post-WWII era. Today, even as the numerous benefits of high connectivity are becoming increasingly recognized, the auto-centric standards of yesteryear remain firmly dominant, particularly in the field of traffic engineering.

Traffic engineering standards discourage small blocks and frequent intersections because of safety concerns. Many jurisdictions have codified those standards into their planning regulations for suburban construction, with the result that most new development consists of isolated pods depending from highway-size arterials. It is a profoundly auto-oriented pattern that is hostile to pedestrians and bicyclists. It creates the typical suburban landscape of separated, isolated pockets instead of the continuous fabric of streets and blocks that is characteristic of efficient, walkable towns and cities.

Are the safety objections against high connectivity grounded in reality? Several investigations suggest that the position promulgated by mainstream traffic engineering standards can be legitimately questioned. Because this is a new and somewhat revolutionary avenue of thought, formal statistical support is just beginning to be compiled. The initial round of studies has found that livable, walkable neighborhoods with well-connected streets are no less safe, and in some respects are safer, than the standard suburban template.

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This is part 6 of a series. See also Introduction • Historical Background • Latter Half of the 20th Century • Neighborhood Walking • Neighborhood Crime • Crash Safety

Automobiles have brought many benefits to society, and at the same time there are many good reasons to reduce the number of vehicle miles traveled (VMT) each year. Thoroughfare connectivity is part of the strategy that reduces VMT; it is a necessary, but by itself insufficient, component of walkable environments. Also, well-connected thoroughfares can reduce traffic congestion by providing alternate travel routes, and can speed emergency services by providing more direct routes and better accessibility.

There’s a nascent movement to advance better-connected thoroughfares, but meanwhile the inertia of preexisting standards and regulations discourages or prohibits high connectivity for most new construction. In addition, NIMBY residents are frequently opposed to new street connections. Future trends in energy, environmental and cultural conditions, however, could lead to walkable, well-connected thoroughfare layouts becoming more customary.

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This is part 5 of a series. See also Introduction • Historical Background • Latter Half of the 20th Century • Neighborhood Walking • Vehicle Miles and Traffic • Crash Safety

In America for a long while now, the conventional wisdom has been that isolation equals safety. In that viewpoint, one achieves maximum safety in a home that is hidden from public view, located on an isolated cul-de-sac, placed in a walled, gated community, and removed from the center city to the far exurban fringes of the metro area.

But does that model provide the best security in all situations? Or does designing for isolation sometimes provide an illusion of security?

Burglaries and street crime result from a nexus of factors, including demographics, individual psychology, and environment. Design plays a role as well. The conventional assumption is that greater isolation protects against crime, but researchers are finding that long, isolated cul de sacs with homes that are not visible from the street have higher crime rates. Crime researchers recommend breaks in the street network only under certain limited conditions.

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