Trends in urban travel demand and their links to regional structure

In this section we consider recent empirical evidence for the Central Ontario Zone that illustrates in greater detail the travel demand-regional structure interaction discussed in general terms in the previous section. The focus of the discussion in this section is on trends in person travel. This focus reflects both the greater availability of data for person travel relative to what is available for goods movements, as well as a sense that, perhaps, urban form may have a greater direct impact on person travel than it does on goods movements. Section 4 below, however deals briefly with goods movements and their links to regional structure.

In aggregate, person travel demand is influenced primarily by:

  • socioeconomic and demographic characteristics (including, notably, auto ownership levels);
  • the distribution of population and employment;
  • development densities for both residential and commercial areas;
  • work trip patterns;
  • the network of road and transit facilities and services available.

In terms of modal choice, the competitiveness of public transportation relative to the private automobile depends primarily on the relative travel time, convenience, and cost for the entire door-to-door trip as influenced by transit route configuration, service levels, and fares, as well as the degree of integration (or "seamlessness") among various service providers. In much of the Central Ontario Zone (especially outside the GTA), current transit service, if it exists at all, typically is not competitive in terms of door-to-door travel time with the private automobile, and may also be more expensive on a perceived out-of-pocket cost basis as well,6 at least for trips that are not commuter trips into the Toronto central area.

The ability to provide cost-effective public transportation services that might compete with the private automobile depends primarily upon the travel patterns to be served - the general pattern of origins and destinations being the determining characteristic. Travel patterns are strongly influenced by land use, automobile ownership, demographic characteristics such as age and income, and by the spatial and service characteristics of the transit network itself, all of which are highly interrelated. Other factors, including pricing and special regulations such as priority treatment for transit vehicles, also influence transit attractiveness and effectiveness.

Thus, a classic supply-demand relationship exists in which the number of people using transit depends on the level of service which the transit system can provide relative to the auto option, but this level of service depends upon attracting sufficient patronage to make the service cost-effective. Land use and urban form primarily determine the outcome of this supply-demand interaction by determining the spatial pattern and concentration of travel flows and, hence, the suitability of transit for serving these flows.

Non-motorized modes of travel (walking, bicycling) are also important for short trips: 28% of all 2001 work and school trips with a straight-line distance of 5 km or less in the Central Ontario Zone were made by walking or cycling.7 The benefits associated with such trips are considerable in terms of personal health, the lack of negative environmental impacts, reductions in the load on road and transit systems, and travel cost savings, while the societal costs associated with non-motorized travel are often negligible.8

For non-motorized modes to be an effective alternative to motorized travel requires (a) a land use pattern in which a mixture of activities co-exist within reasonable walking or cycling distances and (b) a micro-level neighbourhood street and building design that facilitates and encourages walking and cycling. These two prerequisites may exist at virtually any level of urbanization, from the small town or village right up to the densest urban centre.

A number of recent studies have documented current person travel demand patterns and trends in the Central Ontario Zone (or portions of it, such as the GTA or the GTA+H) and their implications for congestion, pollution, and greenhouse gas emissions. A selected bibliography of these studies can be found at the end of this paper. In the remainder of this section, we summarize the findings from these more detailed studies, with an emphasis on their implications for the transportation-land use interaction and for the formulation and implementation of smart growth policies.

6. Automobiles are expensive to own and maintain (Miller, et al., 2002). The perceived cost of making an individual trip by car, however, is generally quite small, particularly if parking at the non-home end of the trip is free. One estimate of the perceived cost of auto travel which has been used to model mode choice behaviour in the GTA is 6.5 cents/km (1996 dollars) (Miller, 2001). In 1996 the average adult TTC fare was $1.71, however, which means that an individual would have to travel 26 km before the perceived cost of the trip by car within the TTC service area equalled the transit fare, in the absence of parking charges.
7. One weakness of the TTS is that travel on foot is documented only for trips to work and school. Comparable statistics for non-work/school travel cannot be reported.
8. Safety concerns, especially about using bicycles in mixed traffic streets, exist. Also, retrofitting bicycle lanes within an existing street system, or improving the "walkability" of a previously developed neighbourhood, clearly involves some capital costs.