Smart Growth America and Taxpayers for Common Sense have just released a report entitled Repair Priorities: Transportation spending strategies to save taxpayer dollars and improve roads. The report basically makes the point that many of the existing roads are not in good shape, and that it would be most cost-effective to repair the existing roads before they deteriorate further. However, states have a tendency to build and expand new roads before caring for existing ones. New construction means more road to maintain later on, adding to the financial burden. According to the report, Tennessee has 30% of roads that are in less than good condition. Between 2004 and 2008 though, it spent $487 million on new construction and $116 million on maintainence.
Walking and cycling facilities are frequently included in new construction, and are less likely to be added to a maintainence project. Retrofitting existing streets to make them more pedestrian and cyclist friendly is sometimes difficult to impossible, depending on traffic volumes and speeds. However, where retrofitting is possible is often where significant progress can be made at minimal cost. Road diets that take one underused lane and convert it into bidirectional bike lanes are one example; if there is substantial turning traffic, simply restriping the road to have dedicated left/right turn lanes and pockets frequently means that a three lane road can handle as much traffic as a four lane, and be safer even for cars. Narrowing existing lanes to widths of 10-11 ft (termed a lane diet) sometimes would permit the striping of bike lanes. Even if bike lanes cannot be accomodated, a cycling-friendly wide outside lane of 14-15 ft may be possible. The key point is that with maintainence that needs to be done anyway, simple reconfigurations require nearly zero construction cost. With today's tight transportation budget, such savings are crucial. Portland, OR was able to take advantage of such "low-hanging fruit" in order to obtain their network for a grand total of around $60 million.