Demystifying Extended Design Domain (EDD) Applications

Abstract

There are situations where the application of higher order road design principals become impractical or even unachievable due to a combination of constraints. “All road design is a compromise between the ideal and what is a reasonable outcome eg in terms of cost, safety, driver expectation, economic drivers, environmental impacts and social issues” (Transport Association of Canada – adopted by Queensland TMR). Austroads has provided guiding principles for designers and engineers to enable them to investigate a safe alternative for situations that do not fully fit within the normal design domain guidelines. Extended Design Domain (EDD) offers a robust process with reasonable capability still afforded to the travelling public.