50 Street is an important goods movement and commuter corridor in the City of Edmonton (City), providing access to adjacent developing industrial areas and functioning as a major north-south commuter route. Currently, the at-grade Canadian Pacific Railway (CP) crossing along 50 Street north of Sherwood Park Freeway ranks as the top priority location for grade separation in the City based on delays, number of vehicles impacted, frequency of train crossings and other factors.
With ongoing development along the 50 Street corridor, particularly in the industrial and residential areas south of Sherwood Park Freeway, traffic volumes and congestion at this crossing are predicted to continue to increase. The City, along with ISL Engineering and Land Services Ltd. (ISL), recently completed a concept validation study for the grade separation of the CP crossing of 50 Street NW near 82 Avenue NW. The scope of the project was to review, validate and update the previously completed grade separation feasibility study (2008) and subsequent 50 Street Corridor study (2010), which both recommended a tight urban underpass. The project complexities included being situated in a fully developed and built up area of the City with existing residential, commercial and industrial land uses abutting the corridor, existing at-grade accesses within the grade separation area, complex underground and aerial utilities, a high water table, sand lenses in the sub-surface, and numerous daily train movements across 50 Street both from the CP mainline and from shunting in and out of CP’s Lambton staging yard, which also abutted 50 Street This paper will present the process that the City and the project team undertook to explore feasible and viable options, both overpass and underpass, as well as the decision making processes that were used to select the preferred option.
This paper will highlight the issues, opportunities, challenges and constraints that resulted with the overpass and underpass options, as well as the sub options that were explored to reduce costs and present a viable, constructible project. In addition, the paper will present the implementation approach along with the risk assessments, value engineering, and multiple account evaluation process that were undertaken. The paper will demonstrate how the City and the team undertook the exploration of options for a complex project in a constrained corridor and ultimately recommended a refined underpass option that met stakeholder concerns, respected access needs (both during and post construction), and minimized land acquisition and overall costs.