The Institute of Transportation of Engineers (ITE) and the Congress for New Urbanism (CNU) have together produced a design manual for engineers, city planners, public works departments, and other community members. The manual, called Designing Walkable Urban Thoroughfares: A Context Sensitive Approach is available for free download and has so far been popularly received.
At ITE's recent annual meeting, as reported in New Urban Network, CNU identified several counterintuitive and overlooked advantages that narrow streets have over wider ones. As pedestrians have less crossing time, cars will have less wait times and thus road capacity can actually be increased. As a result, cars will be able to go at a slower speed and have to stop less frequently. Narrower roads for pedestrians means that it is safer because they cross mid-block to only two lanes of traffic. Another major boost to pedestrian safety is increasing signal countdown timers which have been shown to reduce crash rates by 25%. According to CNU, wider arterial streets with few intersections are less versatile than traditional networks that have shorter blocks and a grid-like pattern.