For effective stimulus, promote street networks
ROBERT STEUTEVILLE    JAN. 1, 2009
The new US administration’s economic stimulus plan is sometimes framed as a battle between roads and transit. The Congress for the New Urbanism (CNU) has a sensible proposal to bridge that divide — if anyone is listening. While the CNU supports more funds for transit, it notes that road expenditures are also environmentally sustainable if targeted properly. “Well networked streets reduce energy consumption and greenhouse gas emissions — goals that are at the forefront of President-elect Obama’s agenda,” writes John Norquist, President and CEO of CNU, in a letter to US Rep. James Oberstar, chairman of the House Transportation and Infrastructure Committee. As the research shows on page 1, these networks also save lives — California cities with highly connected street networks have roughly one-third the fatal accidents of those with poorly connected networks. The idea is to designate areas of cities and towns with high network connectivity. Essentially, any section of a town with a fine-grained street network would meet the standard. These areas — exemplified by classic street grids built before 1950 — would be automatically eligible for stimulus funds, with priority given to projects that improve connectivity and walkability. Projects that improve connectivity in so-called emerging networks — areas where improvements would enable them to meet the threshold — would also be funded, according to the plan. Developing areas with new urban plans would fall into that category. Local streets handle 50 percent of all vehicle miles traveled and the majority of walking and bicycling trips, yet are largely left out of federal transportation spending, CNU notes. “In most cities and towns, the capacity on local streets surpasses the capacity on roads that are eligible to receive federal funding,” CNU states. Networked streets serve transit, pedestrians, and bicyclists, and provide frontage for housing and retail. Their connected nature not only offers tremendous automobile capacity — it distributes traffic evenly, relieving congestion. The network approach is an alternative to the current system, in place since the 1950s, of “prioritizing and building singular facilities,” CNU states. Facility improvements of the sort that transportation departments have usually built often result in more vehicle travel and congestion. Adding a vehicular lane, for example, often diminishes the appeal of walking on that thoroughfare. The facilities approach ignores street networks, resulting in underuse of many thoroughfares and excessive traffic on others, CNU says. The designation of network areas would be based on the following criteria: Existing network areas Street system connectivity is determined by the number of intersections per square mile, minus the number of dead-end-serving intersections. Qualifying areas must have 150 intersections/square mile. The standards include junctions between 1) two streets, 2) a street and an alley, and 3) a street and a multiuse pathway (up to 10 percent of total intersections). These criteria match the street connectivity requirements in LEED for Neighborhood Development, the nation’s first certification system for green development at the neighborhood scale. Projects must demonstrate a sufficient level of street connectivity in order to be certified as green developments. An extension of the nation’s leading green building certification system, LEED-ND was developed through a partnership of the US Green Building Council, the Natural Resources Defense Council, and CNU. The rating system is currently undergoing public comment and is predicted to launch in mid-2009. Emerging network areas These areas do not currently meet the standard of 150 intersections per square mile but would meet the standard through completion of connectivity enhancement projects. Connectivity enhancement projects Within the network areas, this measure gives priority to the following types of projects: 1. Connectivity enhancements: These projects increase the number of intersections per square mile by removing gaps in the network. 2. Road diets: These projects reduce the number of lanes or lane widths to accommodate more pedestrian capacity and/or improve vehicular speed on the roadway. 3. Intersection diets: These projects add pedestrian bulb-outs and remove right-hand turn lanes so that the crossing distance for pedestrians is reduced. 4. Decrease block size: These projects add streets to large, underused projects, like grayfields and brownfields. 5. Sidewalk enhancements: These projects increase sidewalk width and/or improve pedestrian amenities. 6. Two-way conversions: Projects that replace one-way streets with two-way streets. 7. Context-sensitive design: Projects that use the approach outlined in the Institute of Transportation Engineers’ Context Sensitive Solutions in Designing Major Urban Thoroughfares for Walkable Communities. Note: For more commentary on sustainable infrustructure investment, see page 23.