8. The range of local street types should be broad enough to allow a great deal of <br /> flexibility for residential developers, thus discouraging the construction of private <br /> streets. <br /> 9. Local street layout should permit and encourage efficient lot layout and attainnient <br /> of maximum densities. <br /> 10. The function of the local street should be readily apparent to the user through its <br /> appearance and design. <br /> 11. The layout of a local street system should not create excessive travel lengths. <br /> 12. Local circulation systems and land development patterns should not detract from <br /> the efficiency of adjacent collector or arterial streets. The local street system should <br /> be designed for a relatively uniform low volume of traffic, i.e., provide for optimum <br /> dispersal. Collectors, however, should be designed to accommodate peak periods of <br /> demand. <br /> 13. Large scale, high - canopy street trees should be planted on local streets to create <br /> attractive and healthy neighborhood environments. Damage to street trees resulting <br /> from utility line placement and repair, and from new home construction, should be <br /> minimized. <br /> 14. Streets identified as future transit routes should be designed to safely and efficiently <br /> accommodate transit vehicles, thus encouraging the use of public transit as a <br /> transportation mode. <br /> Sources consulted in development of these principles include Residential Streets, published in <br /> 1991 by the American Society of Civil Engineers, National Association of Homebuilders, and <br /> the Urban Land Institute; Performance Streets: A Report on Supplemental Street Standards for <br /> Residential Neighborhoods in Houston prepared in 1994 by Peter H. Brown Civic Design; <br /> Performance Streets: A Concept and Model Standards for Residential Streets, prepared by the <br /> Bucks County, Pennsylvania Planning Commission (1980); and the City of Boulder, Colorado <br /> Residential Access Program materials (1994). <br />