Proposed Changes to PDDM

A new draft of the entire PDDM has been posted. All chapters have formatting changes, typo fixes, link updates, and units rearranged as US Customary [Metric]. The following chapters of the PDDM have additional draft changes awaiting comment and approval:

Chapter 1: INTRODUCTION

The following changes are proposed:

  1. Section 1.1.4 - Modified text to state that the PDDM is published in US Customary units with SI units in square brackets (the reverse of the original convention)
  2. Section 1.1.5 - Changed FDL to FLH Discipline Champion (or Champion for short). Removed FDL from Section 1.4.1 abbreviation listing.
  3. Section 1.2.5 - Removed link to Clearview Typeface since this has not been generally approved by FHWA.

Chapter 3: ENVIRONMENTAL STEWARDSHIP

The following changes are proposed:

  1. Removed links from obsolete documents.

Chapter 4: CONCEPTUAL STUDIES AND PRELIMINARY DESIGN

The following changes are proposed:

  1. Used section numbers to refer to the 2011 Green Book
  2. Section 4.3.2.3 - modified definitions
  3. Section 4.6 to 4.6.2 - updated text
  4. Section 4.7.1.1 - added sentence
  5. Section 4.7.1.3 - added section on Pavement Preservation. Current Sections 4.7.1.3 to 5 became 4.7.1.4 to 6.
  6. Section 4.7.1.5 - minor edits
  7. Section 4.8.1.5 - added discussion of Earthwork Design
  8. Section 4.9.2.2 - Removed references to the NPS Value Based Decision-making document (could not be found on the web)

Chapter 5: SURVEYING AND MAPPING

The following changes are proposed:

  1. Changed FLH standard to include FGDC National Standard for Spatial Data Accuracy..

Chapter 6: GEOTECHNICAL

The following changes are proposed:

  1. Section 6.6 - Changed reference from FHWA-IF-99-025 to GEC-10, FHWA-NHI-00-043 to GEC-11, and FHWA-NHI-00-044 to FHWA-NHI-09-087.

Chapter 7: HYDROLOGY AND HYDRAULICS

The following changes are proposed:

  1. Removed refences to the "ohm-in" unit.
  2. Exhibit 7.1-A - Added section for Outlet Protection under ROADWAY HYDRAULICS. Moved Energy Dissipators section under RIVER HYDRAULICS
  3. Changed references to National Flood Frequency (NFF) to National Streamflow Statistics (NSS)
  4. Section 7.1.3.1.1 - added new section
  5. Section 7.2.1 - link to Terraserver USA removed. This site and its successor (MSR Maps) were both closed.
  6. Section 7.3.1.5.3 - rewrote section
  7. Section 7.3.2.4.3 - added erosion protection information
  8. Section 7.3.3.3.1 - Added criteria for roads with narrow shoulders
  9. Section 7.3.4.4.3 - rewrote section
  10. Section 7.3.5 - section reconfigured as Outlet Protection. Discussion on Energy Dissipators moved to Section 7.4.9.
  11. Exhibit 7.3-B - enlarged figure and made it dual units.
  12. Section 7.4.3 - changed the flood frequency and added additional information (including a new exhibit) on scour countermeasures.
  13. Section 7.4.6 - edits made to text
  14. Section 7.5.1 - section renamed and minor modifications to text
  15. Section 7.5.4.1 - modified section

Chapter 9: HIGHWAY DESIGN

The following changes are proposed:

  1. Minor changes throughout (unmarked)
  2. Used section numbers to refer to the 2011 Green Book
  3. Section 9.1.4 - Added section on variances to standard practice. Existing Section 9.1.4 became 9.1.5.
  4. Section 9.3.1 - Additional discussion on design controls, functional classification, local roads. Added a new Section 9.3.1.2.6 on special routes. Divided Section 9.3.1.9 into subsections with new content.
  5. Section 9.3.8 - Reformatted Section 9.3.8.4
  6. Section 9.3.14 - Added new Subsections 9.3.14.4.5 and 9.3.14.4.6
  7. Section 9.5.2 - Added Subsection 9.5.2.3.7
  8. Section 9.6.9 - Removed most of section and referred to other FLH documents.

Chapter 12: RIGHT OF WAY AND UTILITIES

The following changes are proposed:

  1. The FHWA Appraisal Guide no longer exists. References to the guide were removed from Sections 12.2.2, 12.8.4.2, and 12.8.4.4.
  2. The AASHTO Right of Way and Utilities Guidelines and Best Practices no longer exists. References to this document were removed from Sections 12.1.1.3, 12.2.2, and 12.3.