In the spirit of Monday’s car-free day, this post asks the question: are those who earn higher incomes more likely to drive to work? Using 2006 Canadian Census tract data for the island of Montreal, I’ve created a map showing the city’s distribution of median personal income (after-tax), along with a map showing the percentage of workers who commute by walking, biking, or public transit. The third map merges the two…
Generally, higher income is significantly associated with higher percentages of car-commuters (no surprise there). However, there are areas within Montreal where both low median incomes and low percentages of non-car commuters are found. Basically, a few neighbourhoods with lower median incomes have residents who are likely to rely upon personal cars for commuting to work- a costly expense.
The following map shows the median personal income level (in dollars) of each census tract according to the 2006 census. For example, the neighbourhoods of Westmount and Beaconsfield have predictably higher median incomes, while St. Michel and North Montreal show a lower amount. The areas in green are either parks or tracts with no data.
Next, this map shows the percentage of residents per census tract who walk, bike, or ride public transport to work. As expected, people who reside in areas away from the central business district and metro lines (I’ll show the metros next time) are more likely to drive to work.
In the following map, I use a spatial statistic (a local spatial autocorrelation) to find interactive clusters of median personal income and non-car commuting. Red areas show where high income is matched with high levels of non-car commuting. Red census tracts in Westmount and parts of the Plateau show areas with relatively high median incomes near downtown, and where people often do not drive to work. The light red areas are where higher incomes are paired with higher usage of cars, and as expected are at both ends of the island. The light blue areas show where lower levels of income are matched with low car usage. The white areas have no statistically significant clustering.
Noteworthy areas on this map are the dark blue pockets: these census tracts have lower median incomes and also show low percentages of non-car commuters. While the general trend is for higher-income census tracts to have higher levels of car commuters unless directly downtown, these areas have lower median incomes and yet rely upon automobiles.
Essentially, there is a possibility that these areas are not adequately serviced by public transit, or that other forms of non-car commuting are not readily accessible.
These maps are largely descriptive, in that there are many factors involved as to whether one drives to work or not. Furthermore this data is at the census tract level and does not describe individuals or households directly, and can only give a general percentage or statistic for a small urban area. This publicly available data is compiled from Statistics Canada through the University of Toronto’s CHASS system, and the geographic files are provided by the EDRS at McGill.