You may have noticed that transportation seems much more expensive than you're used to paying, especially for public transit. For example, 4 km on the 99-B Line cost $5.17 per passenger -- more than the actual bus fare.
Similarly, walking seems like it should be free because you're not actually paying anyone any money.
That's precisely the point of adding up all the true costs of transportation, since there are so many 'hidden' costs that we typically don’t consider when planning our daily commutes. Walking, for example, takes more time per kilometre than travelling in other ways. This calculator assigns an hourly wage to your travel and wait time.
Different ways of travelling carry different costs and benefits. Some of those are borne by the individual, like travel time, transit fares and automobile maintenance. Some are carried by society through collective taxation, like the costs of treating accident victims or managing the impacts of air pollution. In some cases, certain ways of travelling offer a benefit to society. For example, walking and cycling save society money through the benefits of improved health as a result of exercise.
This calculator aggregates many different sources of data for one sum cost of a commute. It includes information such as medical expenditures, costs of building and maintaining road infrastructure, costs of congestion, pollution and much more.
A detailed definition of all the costs can be found here.
When the commute cost appears as a negative (-), there is a net benefit to the user or to society, rather than a cost. That means that what is paid (for example, fares, taxes, fuel or maintenance costs) is offset by what is gained. Active forms of travel like walking and cycling carry overall benefits to society, due to savings in healthcare costs and increased productivity at work. While traveling by bus doesn’t include direct savings to society, in some cases (depending on the number of passengers that take that bus) the cost to run that bus per person is less than each of those people pay in fares.