Chapter 4: Non-Freeway Rehabilitation (3R) Design CriteriaAnchor: #BABHCECC
Section 1: PurposeAnchor: #i1005493
The basic purposes of resurfacing, restoration or rehabilitation (3R) projects are to preserve and extend the service life of existing highways and streets and to enhance safety. Because of limited resources, individual rehabilitation projects may have to be limited in scope in an effort to preserve the mobility function of the entire highway system. The scope of 3R projects varies from thin overlays and minor safety upgrading to more complete rehabilitation.
3R projects are those which address pavement needs and/or deficiencies and which substantially follow the existing horizontal and vertical alignment. They differ from reconstruction projects in that reconstruction projects substantially deviate from the existing horizontal and/or vertical alignment and/or add capacity.Anchor: #i1005509
Design guidelines for 3R projects have been developed to allow greater design flexibility. At the District’s option, design values above those presented in this chapter may be used.
These guidelines offer sufficient flexibility to ensure cost effective design and further compliance with the program goals of preserving and extending the service life and enhancing safety. While safety may not be the primary reason for initiating a 3R project, highway safety is an essential element of all projects. These 3R projects are to be developed in a manner which identifies and incorporates appropriate safety enhancements.
For the purpose of 3R projects, current average daily traffic (ADT) volumes of less than 1500 are defined as low traffic volume roadways.