Geometric design practices in Canada continue to evolve rapidly since the Transportation Association of Canada (TAC) released the major revision of the national Geometric Design Guide for Canadian Roads in late 1999. At that time, the TAC Guide introduced the Design Domain concept that provided additional flexibility for designers and emphasized the need for explicitly evaluating the road safety performance impacts of geometric design decisions whenever possible. This paper examines the continuing evolution of Canada's geometric design practices across the country since 1999 and the emerging issues that appear to be driving the development and adoption of enhanced practices in a number of technical areas. Three issues in particular seem to be emergent and influential: developing community pressures for context sensitive design approaches in both urban and rural areas; the desire to better recognize the needs of vulnerable road users (pedestrians, cyclists, etc.) within the geometric design context; and the ongoing desire to provide more cost and operationally effective designs within the constrained design environments faced in many major rehabilitation and restoration projects. The impacts of these emerging issues, and the practical design responses of various Canadian jurisdictions to them, are reviewed through a series of examples from across the country that both illustrate and underline the importance of these pressures and the needs they generate for new design tools and approaches that respond to them. In the penultimate section of the paper the implications of these new developments on research needs for the geometric design of roads are discussed. The need for tools that help further enhance the linkage between the design process and the explicit evaluation of road safety performance emerges as a continuing challenge, and the potential role of technologies such as the Interactive Highway Safety Design Model (IHSDM) are examined in this light. In addition, the growing importance of developing and incorporating design processes that recognize the need for a better understanding of the influence of human factors on design decisions is stressed. A number of other needs are also identified. The closing section of the paper provides an overview and summary of key national directions and their implications for the practice of geometric design in Canada.
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