Chapter 4, Cross Section Elements of TAC’s Geometric Design Guide for Canadian Roads (GDG) addresses design procedures and domains related to road cross sections (e.g. lane widths, special purpose lanes, shoulders, medians, outer separations and boulevards, curb and gutter and drainage), and presents typical cross sections as well as discussing considerations related to bridges, utility placement, snow storage and future widenings.
The 2017 update of TAC’s GDG did not incorporate major revisions to Chapter 4, which was previously updated in 2001. Volunteers on TAC’s Geometric Design Committee have completed a comprehensive review of the existing Chapter 4 and identified a number of sections that require updating, notably those pertaining to urban contexts. The working group also conducted a high-level survey of TAC member organizations that confirmed the need for both updated and new information in Chapter 4 to help respondents reduce their reliance on supplementary sources of design guidance.
This project represents the first phase of work needed to develop a new GDG Chapter 4, Cross Section Elements. A subsequent phase of work would be required to draft and finalize text, figures and tables for the new Chapter 4.
The major objective of this project will be to research and synthesize current practices related to road cross section design in Canada, including those related to the following road elements:
Other issues to be addressed include:
The tasks included in this phase of the Chapter 4 update will include:
The final deliverable of this project will be a research report documenting relevant practices and considerations related to cross section design for Canadian roads.