This paper was presented at the session titled `Risk management in the roads sector - geometric design'. Road authorities have traditionally addressed road safety design issues by making improvements to existing roads. When improvements are being considered to an existing roadway, there may be other safety concerns related to the proposed improvements. Increasingly, these safety concerns are being identified and addressed at the design stage, through road safety audits or assessments. This paper describes a recent application of this process to a major corridor in the City of Edmonton. The Yellowhead Trail is a major east-west route across the north part of Edmonton. The City of Edmonton has been planning improvements that will ultimately upgrade this important corridor to freeway status. As the costs involved to free-flow a facility like Yellowhead Trail are significant, interim actions are necessary to accommodate the growth safely and efficiently until such time as funding is available for full grade separation. In mid-1999, the City proposed a set of interim actions to improve mobility and safety along the Yellowhead Trail segment between 156 Street and 82 Street. This segment contains a mixture of interchanges, signalised intersections and unsignalised intersections. These interim improvements included the closure of some at-grade intersections, the introduction of turn restrictions, and geometric improvements, as described in the publication Yellowhead Trail Facility Planning Study Review, A Discussion Document on Proposed Interim Actions to Improve Safety and Traffic Flow (June 1999). The proposals were aimed at improving Yellowhead Trail by addressing safety issues associated with vehicles entering directly onto the corridor, improving traffic flow through intersection improvements and signal co-ordination, and establishing a framework for consistent traffic access management standards along the corridor. As part of the planning and public consultation process that was conducted for these interim improvements, the City commissioned an innovative safety assessment of the proposed improvement strategies, to explicitly identify the positive safety impacts of the project, and to determine any areas of concern related to road safety risk being introduced due to the proposed network changes. The study consisted of three stages: an overview of the existing traffic and collision patterns along the corridor; estimate of the safety implications associated with the proposed interim actions; and identification of possible safety enhancements to the proposed interim actions. (A)
Abstract