For several reasons, the territories defined in the Ontario government's discussion paper on UGCs were of little assistance in performing this analysis (Ontario, 2005c). The document relies on municipal territorial definitions of downtowns, cores, or nodes. The problem with these definitions is their inconsistency, which accounts for a wide variation in the size of UGCs (from 3 km2 to 26 km2). Also, notwithstanding this diversity, UGCs tend to cover large areas -- 9 km2 on average. Large areas no doubt reflect the economic development objectives pursued by municipal administrations when delineating their downtowns, cores, or nodes. The larger the area, the more likely it will attract fiscally lucrative land uses enticed by downtown, core, or nodal locations. Meanwhile, planning goals, such as the creation of a pedestrian- and transit-supportive environment, risk being relegated to a secondary role. The discrepancy in the size of such areas suggests an absence of a common understanding among municipalities about the nature and purpose of these areas. Moreover, it is unrealistic to expect that high-density multifunctional environments generating the pedestrian-based synergistic effects associated with downtowns, cores, or nodes will ever materialize in suburban districts as large as those found in municipal definitions.
Another difficulty with the way in which UGCs are currently defined is the absence of consideration for their different sectors and for the varied planning treatment each demands. Such large areas are necessarily composed of specialized districts, two of which, found in all UGCs, are residential areas and cores that provide a mixture of activities.
In the report, different approaches were used to delineate the different categories of study areas, and in some cases these methods varied according to the variables under consideration, owing to inconsistencies in the geographic scale at which data are available. The boundaries of the study areas used for particular analyses are mapped in the following pages.
Downtown Toronto is defined as the area contained within Spadina Avenue to the west, Bernard Avenue, Davenport Road and Rosedale Valley Road to the north, Jarvis Street to the east, and Lake Ontario to the south. This area includes downtown-related functions (offices, retailing, and higher-order institutions) as well as high-density housing. However, data pertaining to the nature of the built environment are collected exclusively within four parts of downtown Toronto known for their exceptionally elevated levels of pedestrian movement. The four districts will provide a benchmark for a discussion of the built environment of the other study areas in terms of their ability to encourage walking.
The delineation of the nodes under investigation is more complex than that of downtown Toronto. Using aerial photographs, the boundaries of nodes were drawn to include all contiguous areas serving nodal-related functions: retailing, offices, public-sector establishments, and high-density residential developments. Ancillary land uses, such as parking and the grounds of apartment buildings, were included. The resulting areas provide the basis for measurements of the built environment. By using census dissemination areas, it was possible to aggregate most of the census data (population, employment, housing types, and socioeconomic variables) at this scale. These territorial definitions also served to gauge the internal capture of the three suburban nodes among their office workers. However, because the boundaries of dissemination areas have changed over time, census tracts are used to measure population changes, even though the census tracts that cover the nodes (as defined using aerial photographs) often extend well beyond these areas. In consequence, the census tract-based definition of nodes includes low-density residential areas. A similar issue complicates the use of traffic zones for the identification of journey patterns. For reasons of consistency, traffic zones were harmonized as much as possible with the extended, census tract-derived definition of nodes.
The two small downtowns were also initially delineated using aerial photographs, which permitted the identification of areas dominated by downtown-type functions -- mostly offices and retailing. Built environment measurements relied on these territorial definitions. The areas from which census statistics are drawn also include adjacent residential areas, which were built at approximately the same time as the downtowns themselves and are at a comfortable walking distance from these downtowns. The identification and delineation of these residential areas involved an observation of aerial photographs as well as census information on the age of residential structures. In all cases, these neighbourhoods were clearly bordered by arterial roads, natural features, or industrial areas. Finally, as in the case of nodes, longitudinal data are taken from census tracts that reach beyond the neighbourhoods, and journey data come from traffic zones harmonized with these census tracts.
The Yonge Street density corridor runs from the CP railway line between Bloor Street and St. Clair Avenue (which can be considered the northern edge of an extended definition of downtown Toronto) to Brooke Avenue to the north (between Lawrence Avenue and Wilson Avenue). This northern limit marks the transition from a street-oriented environment to a lower-density suburban-type layout. As defined here, the corridor is six kilometres long and approximately two kilometres wide, and incorporates the Yonge-Eglinton node. Statistics for this node thus appear twice: first for the Yonge-Eglinton node itself, and second, blended with the Yonge Street corridor data. All statistics for the Yonge Street corridor come from census tracts bordering on Yonge Street between its northern and southern boundaries. Traffic zones were matched with the census tracts.
The Mississauga East density corridor covers an area bordered to the west by Confederation Parkway, to the north by Burnhamthorpe Road, to the east by the City of Toronto border (the Etobicoke Creek), and to the south by Dundas Street. The corridor is seven kilometres long and two kilometres wide. A portion of Mississauga City Centre, south of Burnhamthorpe Road, which includes office and high-rise residential buildings, is included in the Mississauga East corridor. Census tracts are contiguous with these boundaries, so they, along with corresponding traffic zones, can be used as the areas for all statistical information. No built environment measurement was carried out in the two corridors, because of the lack of emphasis given in plans on their pedestrian connectivity and related synergistic effects.
The features of study areas are, in some instances, compared to those of two automobile-oriented business parks (the Airport Corporate Centre on Highway 401 and Highway 404-North of Steeles Business Parks), representing common suburban workplace configurations. In both business parks, density and journey patterns (the two sets of variables against which study areas are compared to the business parks) correspond closely to their geographical area.