I. Street Design Concepts <br />Complete streets are those that adequately provide for all roadway users, including bicyclists, <br />pedestrians, transit riders, and motorists, to the extent appropriate to the function and context of <br />the street. American streets were once quite successful in this regard. However, for several <br />decades there was a drift towards a focus on the automobile. More recently there has been a <br />growing recognition that minimizing driving delay should not be the only goal of a. roadway and . <br />may even be undesirable depending on the context. Street design is now recognized as an <br />important determinant of neighborhood character and quality of life. This has resulted in growing <br />public pressure to: <br />■ Improve the functionality and appearance of new streets <br />■ Facilitate pedestrian and bicycle travel <br />■ Reduce the potential for speeding and other safety problems without resorting to speed <br />bumps- <br />Introduce desirable design elements, such as landscaped strips and detached sidewalks <br />that are commonly found in older residential neighborhoods <br />■ Use shorter blocks in certain environments, such as along residential, commercial, and <br />downtown corridors, to slow traffic and shorten walking distances. <br />II. Street Width <br />Research' shows that narrower streets result in slower travel speeds. For example, a recent <br />• study conducted in the City of Longmont, Colorado (population 72,000) looked at 20,000 police <br />collision reports to determine the effect of street design in contributing to accidents. The most <br />significant relationship between injury accidents and street design was found to be with street <br />width and curvature. As street widths widen, accidents per mile increase exponentially.2 <br />Additional research has found that3 <br />Figure 1: Relationship Between Pavement Width and Speed <br />45 <br />40 <br />■ Wider streets experience higher <br />a <br />average and 85th percentile <br />s 36 <br />speeds than narrow streets. <br />Residents' perception of the <br />m 30 <br />impact of traffic on quality of life <br />correlates strongly and <br />25 <br />negatively-with speeds. Where <br />speeds are high, residents are <br />more likely to perceive a <br />20 <br />degraded quality of life <br />15 <br />- High Volume, EntrytCollectot St. <br />- Low Volume, Residential St. <br />20 25 30 35 40 46 <br />Source: City of San Antonio, Texas <br />2 Peter Swift, "Residential Street Typology and Injury Accident Frequency" , 2003 <br />3 James Daisa and John Peers, Fehr & Peer, "Narrow Residential Streets: Do They Really Slow Down <br />.Speeds", 1997; and Matthew Ridgway, Fehr & Peers, "Residential Streets - Quality of Life Assessment", <br />1997 <br />is Complete Streets Best Practices <br />October 2005 <br />2 <br />COLLABORATIVE L-, <br />301 <br />421 <br />i <br />