ITE fails by ignoring street widths

Nothing is more important to success or failure of new urbanist projects than street design. The street is the first part of the public realm encountered when leaving the private realm. With poorly designed streets, it’s difficult to imagine residents of traditional neighborhood developments (TNDs) choosing to walk. And without pedestrians, one might as well build a pod. There are many aspects to good streetscape design, including building placement and architecture, sidewalks, planting strips, and the overall street network. However, all is destroyed by overwide streets. It is written in the Institute of Transportation Engineers’ proposed Traditional Neighborhood Development Street Design Guidelines, that “a TND team will not find a simple chart or table of how wide TND streets should be under different circumstances, here or elsewhere.” That’s a pity, because new urbanists in the trenches continuously face local codes demanding ridiculously wide swaths of pavement in front of residential and mixed-use streets with relatively low levels of projected traffic. These codes result from caution and bad assumptions. What happens if cars are parked on both side of a street, a moving van is double parked and a four alarm fire occurs? What if a delivery truck drives by as someone is opening a car door onto the street, and tears the door off? Better not to reduce the 36-foot wide cartway, officials reason, and avoid a lawsuit. The reality is that these fears are misplaced. Drivers avoid obstacles, especially at reasonable speeds. Emergency vehicles are able to respond to crises on tens of thousands of miles of narrow traditional streets throughout the U.S. The age of buildings on these streets testify that decade after decade, generation after generation, life goes on without massive fires and catastrophes. Wide streets have consequences which frequently make them less safe than narrow streets. They promote faster traffic, which due to immutable laws of physics has vastly greater kinetic energy. After brakes are applied, the stopping distance of a car going 40 mph is five times greater than 20 mph (167 feet compared to 33 feet, according to the ITE). And the impact of the faster vehicle is dramatically more deadly to a pedestrian. Cars going less than 20 mph rarely cause serious injury or death to pedestrians, while at 40 mph, the accident is almost always fatal. Most residential streets in the U.S. are designed to guarantee that cars will be traveling at speeds deadly to pedestrians. But these arguments are difficult for new urbanist designers and developers to make, especially when established traffic manuals and/or codes tell officials that wide streets are better. The fact is, a simple chart relating street width and design speed is possible -- and would be a tremendous aid to new urbanists. Such a tool is being developed by Andres Duany, as part of the Operating System of the New Urbanism, but Duany is an architect and town planner. A clear endorsement of narrow streets must come from traffic engineers themselves in order to carry the greatest weight with municipal officials. The ITE committee, led by Frank Spielberg and Rick Chellman, is to be commended for its work on the TND street design guidelines. But when it comes to street widths, the ITE copped out.