pooled fund Projects
In development
Geometric Design Guide for Canadian Roads - New Edition
| Research Area | Geometric design |
| Responsible Council / Committee | Chief Engineers' Council Geometric Design Standing Committee |
| Related TAC publications | |
| Expected Start Date | TBD |
| Expected Duration | |
| Total Funding Estimate | $1,300,000 |
| Project Funding Partners to Date | Saskatchewan Highways and Infrastructure; City of Montréal; Halifax Regional Municipality; City of Calgary; Newfoundland and Labrador Transportation and Works; Northwest Territories Department of Transportation; City of Winnipeg; Prince Edward Island Transportation and Infrastructure Renewal; Alberta Transportation; Manitoba Infrastructure and Transportation; British Columbia Ministry of Transportation and Infrastructure; City of Toronto; Yukon Department of Highways and Public Works; Nova Scotia Department of Transportation and Infrastructure Renewal; New Brunswick Department of Transportation; Region of Waterloo; City of Ottawa |
| Staff Contact | Sarah Wells |
Abstract
A study has been undertaken to assess TAC’s Geometric Design Guide for Canadian Roads and determine the work that would be needed to update this foundational document. As a result of the study, it is recommended that a new edition of the Guide be prepared to replace the current 1999 edition.
In addition to refreshing the entire document, priority areas to be significantly updated or added to the Guide include the following.
Design exceptions:
Increasing constraints in urban areas, environmental factors, cost effectiveness concerns, and growing community demands for context sensitive design solutions, are all putting pressure on road agencies and design professionals to think differently and adaptively about the application of current design practices. Practitioners must be able to recognize and explicitly evaluate differences in road safety performance between design alternatives. Emerging road safety research and knowledge are beginning to provide practical and reliable tools to address safety performance forecasting. The next edition of the TAC Guide will significantly benefit from a major update in this area.
Roadside design:
Research has shown that collisions with fixed objects account for approximately 30% of all fatal collisions in North America and an additional 10% of road fatalities are attributable to non-collision rollovers caused by roadside factors. Roadside design clearly has a key role to play in improving road safety. Research in this area is very active and should be adapted for the Canadian context and addressed in TAC’s guide.
Human factors:
In formulating early geometric design standards, highway designers relied on a common-sense understanding of drivers and used estimates of driver characteristics in mechanistic models to simulate behaviour and calculate design requirements. While this approach worked well for many years, roads have become more crowded and the roadway network has grown more complex. Human error is a contributing factor in crashes, and forgiving geometric design may reduce the severity or prevent many of these crashes. A human factors design principles chapter is needed in the TAC Guide, and relevant human factors references should be incorporated into each section.
Intersections and modern roundabouts:
The geometric design of intersections directly affects both traffic operations and road safety outcomes. As travel demand continues to increase with the increasing urbanization of our population base across the country, intersection designs are also evolving. The increasing use of modern roundabout solutions has brought with it significant safety and operational benefits but is treated in only a cursory fashion in the current TAC Guide. These subject areas need major revisions in the next TAC Guide.
Active transportation:
Accommodating pedestrians, cyclists and disabled persons more appropriately within the road environment is becoming a high and widely supported priority. However, the safety implications of such designs are not always well understood. The current TAC Guide provides insufficient guidance in this area. The next edition should address the accommodation of active transportation on Canada’s road system, which will involve updates and major revisions to many sections of the Guide.
A detailed report of the update scoping study, with more information about reference material and the priority areas described above, is available to those interested in contributing to this major initiative.
It is expected that the project will be conducted by a consultant team or consortium with broad based expertise in geometric design and related subject areas and with experts participating from all regions of Canada.
The project deliverable will be a new edition to replace the 1999 TAC Geometric Design Guide for Canadian Roads, to be published in both English and French. There is a significant market demand for a searchable electronic version of the Guide or a “smart guide” that would incorporate analytical software and decision support tools. As part of the development of the Guide, publication options will be considered.
The Geometric Design Guide for Canadian Roads is considered one of TAC’s flagship documents and is used to varying extents by all road agencies, designers and practitioners in Canada. TAC members are called upon to become partners and contribute to the work that will produce the next edition of the Guide. A funding prospectus is available from the secretariat.