Appendix A - <br />AASHTO - The Policy on Geometric Design of Highways and Streets, <br />References and <br />also known as the "Green Book," is published by the American <br />Resources <br />Association of State Highway and Transportation Officials <br />(AASHTO) and is considered to be the principle authority on street <br />Annotated References <br />geometries. Narrow streets are sometimes cited as being contrary <br />to traffic engineering practices because they may hinder the free- <br />flowing movement of vehicular traffic. However, the Green Book <br />supports the notion of using narrow residential streets. For ex- <br />ample, the Green Book states: "On residential streets in areas where <br />the primary function is to provide land service and foster a safe <br />and pleasant environment, at least one unobstructed moving lane <br />must be ensured even where parking occurs on both sides. The <br />level of user inconvenience occasioned by the lack of two moving <br />lanes is remarkably low in areas where single-family units <br />prevail ...In many residential areas a 26-ft.-wide roadway is typical. <br />This curb-face-to-curb-face width provides for a 12-ft. center travel <br />lane and two 7-ft. parking lanes. Opposing conflicting traffic will <br />yield and pause on the parking lane area until there is sufficient <br />width to pass." <br />Residential Streets - Residential Streets is published jointly by <br />the American Society of Civil Engineers, the National Association <br />of Homebuilders, and the Urban Land Institute. This book was <br />published to encourage a flexible approach to designing residential <br />streets to respond to the street's function in the transportation <br />system as well as part of the community's living environment. <br />Residential Streets is a hierarchy of residential streets, including 22'- <br />24' access streets with parking on both sides, 26' subcollector street <br />with parking on both sides, and a 28' subcollector with parking on <br />both sides where "on-street parking lines both sides of the street <br />continuously." <br />ITE - They Institute of Transportation Engineers (ITE) has pub- <br />lished several documents that refer to the recommended width of <br />neighborhood streets. The 1993 publication Guidelines for Residen- <br />tial Subdivision Street Design states that a 28-foot curbed street with <br />parking on both sides is an acceptable standard. "based upon the <br />assumption that the community has required adequate off-street <br />parking at each dwelling unit." In addition, the 1994 publication <br />Traffic Engineering for Neo-Traditional Neighborhood Design, (NTND), <br />states that the recommended width of a basic NTND residential <br />street "may be as narrow as 28 to 30 feet." <br />Street Design Guidelines for Healthy Neighborhoods - Pub- <br />lished by the Local Government Commissions Center for Livable <br />Communities, Street Design Guidelines for Healthy Neighborhoods was <br />developed by a multi-disciplinary team based upon field visits to <br />over 80 traditional and 16 neo-traditional neighborhoods. When <br />combined with other features of traditional neighborhoods, the <br />guidelines recommend neighborhood streets ranging from 16-26 <br />feet in width. The team found 26-foot-wide roadways to be the <br />most desirable, but also "measured numerous 24-foot and even 22-foot <br />wide roadways, which had parking on both sides of the street and <br />allowed delivery, sanitation and fire trucks to pass through unobstructed." <br />21 <br />111 <br />