National Academies Press: OpenBook
« Previous: Chapter 1. Introduction
Page 16
Suggested Citation:"Chapter 2. What are 3R Projects?." National Academies of Sciences, Engineering, and Medicine. 2018. Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects. Washington, DC: The National Academies Press. doi: 10.17226/25206.
×
Page 16
Page 17
Suggested Citation:"Chapter 2. What are 3R Projects?." National Academies of Sciences, Engineering, and Medicine. 2018. Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects. Washington, DC: The National Academies Press. doi: 10.17226/25206.
×
Page 17
Page 18
Suggested Citation:"Chapter 2. What are 3R Projects?." National Academies of Sciences, Engineering, and Medicine. 2018. Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects. Washington, DC: The National Academies Press. doi: 10.17226/25206.
×
Page 18

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

4 Chapter 2. What are 3R Projects? This chapter discusses the definition of 3R projects and how they differ from new construction and reconstruction projects, the objectives of 3R projects, and typical improvements considered in 3R projects in addition to resurfacing. 2.1 New Construction vs. Reconstruction vs. 3R Projects Understanding of the context for design of 3R projects requires understanding of the distinctions between new construction, reconstruction, and 3R work. Each of these types of projects is defined below. 2.1.1 New Construction Projects New construction projects typically consist of projects on new alignment where no highway facility has existed before (e.g., projects on greenfield sites). Some projects on existing roads might be classified as new construction if the existing roadway is completely removed, a new alignment or cross section is developed for the facility, and the new alignment and cross section are not substantially constrained by development adjoining the existing road; this situation is rare, but can occur. New construction projects are designed using the criteria in the AASHTO Green Book (4). The design guidelines presented here do not apply to new construction projects. 2.1.2 Reconstruction Projects Reconstruction projects include projects on existing roads that are not considered new construction and in which:  the entire pavement structure, down to the subgrade, is removed and replaced, for all or most of the project length,  a substantial proportion of the existing alignment is modified, or  the basic roadway cross section is changed (e.g., expanding an existing two-lane highway to four lanes) Reconstruction projects are designed using the criteria in the AASHTO Green Book (4). The design guidelines presented here do not apply to reconstruction projects.

5 2.1.3 3R Projects 3R projects include projects in which the scope is limited to resurfacing, restoration, and/or rehabilitation of existing roads. 3R projects do not involve new construction or reconstruction, as defined above. Therefore, by definition, 3R projects do not involve a substantial amount of road construction on a new alignment, removal of the entire pavement structure down to the subgrade, realignment of substantial portions of the project, or a change in the basic roadway cross section. If only a limited or isolated portion of a project involves new construction or reconstruction, the remainder of the project can be designed as 3R work. Projects with overlays of any depth and projects involving cold milling to remove an obsolete surface course and/or maintain a pavement surface elevation consistent with vertical clearance design may be considered 3R projects. For purposes of the design guidelines presented in this document, projects may be classified as 3R projects regardless of whether they are funded as part of the Federal 3R program or any other designated 3R program. The design guidelines presented here are applicable to projects that are not considered new construction or reconstruction and involve only resurfacing, restoration, and/or rehabilitation, regardless of the project funding source. Chapters 2 through 5 present general design guidance applicable to all 3R projects. Chapter 6 presents design guidelines applicable to 3R projects on specific roadway types. Chapter 7 summarizes all of the design guidelines. 2.2 Objectives of 3R Projects The primary objective of most 3R projects is to preserve and extend the life of the pavement by resurfacing. Thus, 3R projects are normally initiated because pavement management systems indicate the need for pavement resurfacing. Furthermore, the timing of most 3R projects is set based on the timing of the need for pavement resurfacing to preserve and extend the life of the pavement structure. A few 3R projects are initiated to address needs other than pavement resurfacing and, as long as they do not involve new construction or reconstruction, they can be considered as 3R projects for design purposes. While the primary objective of most 3R projects is pavement preservation, the development of a 3R project provides an opportunity for geometric design improvements to enhance traffic operations, reduce crashes, improve drainage, or improve the roadway or roadside in other ways. The project would still be considered 3R work as long as the design changes do not constitute new construction or reconstruction. It is to the advantage of both the highway agency and the traveling public for any needed design changes to be made in conjunction with the pavement resurfacing project; coordination of such improvements reduces implementation costs and reduces travel delays in work zones, in comparison to implementing separate projects at separate times. Federal guidelines require highway agencies to consider the need for traffic operational and safety improvements in the project development process for 3R projects funded through the Federal 3R program. The guidelines presented in this document show a structured process for

6 considering the need for traffic operational and safety improvements in 3R projects that is intended to focus such improvements on locations where the improvement will be cost-effective. The guidelines indicate that design improvements should not necessarily be made in all 3R projects, but only when engineering analyses confirm that the proposed improvements are appropriate and cost-effective or where a specific need is otherwise demonstrated. 2.3 Typical Improvements Made in 3R Projects in Addition to Resurfacing A broad range of highway infrastructure improvements may be considered in 3R projects in conjunction with pavement resurfacing. A recent survey found that most highway agencies routinely consider the need for specific design improvements intended to reduce crash frequency and severity in 3R projects (7). Another survey identified the types of design improvements most commonly cited by highway agencies as among the top five improvement types made in conjunction with 3R projects (7,8). These include:  Guardrail addition or improvement (including improvement of guardrail end treatments)  Shoulder paving, grading, or widening  Clear zone improvements  Signing improvements  Shoulder or centerline rumble strips  Striping and delineation  Superelevation restoration  Pavement surface condition/friction  Intersection design/turn lanes/turn radius  Roadway/lane widening  Roadside slope flattening These improvement types and others that may be incorporated in 3R projects are addressed in Chapter 6 of these guidelines.

Next: Chapter 3. Process for 3R Project Development »
Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects Get This Book
×
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

TRB's National Cooperative Highway Research Program (NCHRP) has released a pre-publication, non-edited version of Research Report 876: Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects. The report presents an approach for estimating the cost-effectiveness of including safety and operational improvements in a resurfacing, restoration, or rehabilitation (3R) project. The approach uses the performance of the existing road in estimating the benefits of a proposed design improvement and in determining if it is worthwhile. These guidelines are intended to replace TRB Special Report 214: Designing Safer Roads: Practices for Resurfacing, Restoration, and Rehabilitation. The guidelines are accompanied by two spreadsheet tools available for download through a .zip file: one for analyzing a single design alternative and one for comparing several alternatives or combinations of alternatives.

Disclaimer: This software is offered as is, without warranty or promise of support of any kind either expressed or implied. Under no circumstance will the National Academy of Sciences or the Transportation Research Board (collectively "TRB") be liable for any loss or damage caused by the installation or operation of this product. TRB makes no representation or warranty of any kind, expressed or implied, in fact or in law, including without limitation, the warranty of merchantability or the warranty of fitness for a particular purpose, and shall not in any case be liable for any consequential or special damages.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!