Congested Cities Week: Which factors in Cities are correlate to traffic congestion

In the theme of Congested Cities week being hosted by, it would be worthwhile to investigated the correlation between traffic congestion and several other factors in Cities, using the Correlation Heatmap. The Correlation Heatmap custom tool allows you to interact and engage with the data used to compile the PWC Cities of Opportunity report.

The tool allows you to correlate the similarities and dissimilarities in the comovement of different variables—essentially tracking the tendency of two variables to move together or apart—revealing interesting and potentially causal relationships, notable among them shedding light on families of urban economies and how they behave.

For example: Does a significant correlation existing between factors such green space in a city and traffic congestion or between commuting time and public transport costs?

From this we note some of the following interesting conclusions;

  • Miles of mass transit track: As traffic congestion increases, the miles of mass transit being delivered is only correlated by 55%, suggesting that cities are too slow to respond. A similar correlation existing for mass transit coverage.
  • Green space as a % of city area: Positive to note that green space is 34% correlated to traffic congestion, which may imply that cities are seeing green space as a tool to offset emissions. The down side is that they don’t nearly do enough to offset these emissions.
  • Airport to CBD access: With an only 9% correlation, those opposed to an Airport to CBD rail link in Cape Town, are justfied to question the need for and investment in such a luxury, in light of traffic congestion across Cape Town in peak hours.
  • Commute time: Perhaps the correlation heatmap is not flawless, as a 28% correlation between commute time and traffic congestion seems strange. Perhaps this depends entirely on the number of other transit options, their cost, and speed, in a particular city.
  • Carbon footprint: Is the carbon footprint of a city not increased with an increase in traffic congestion? The Correlation heatmap suggests that there is almost 0% correlation.
  • Cost of public transport: This statistic makes more sense. As traffic congestion increases, the cost of public transport moves in the opposite direction entirely i.e. becomes cheaper. This may be a response by cities to improve the marketability of public transport as an option when commuting, possibly fueled by rising fuel costs.

You have control. Use it to choose the variables that matter to you and build your own data charts.

Share them with colleagues and friends, or print them out for further use. Of course, remember to download the Cities of Opportunity report in its entirety, or select from the interviews, policy analysis, or indicator discussions.