Traffic congestion costs the average driver about $2,500 per year in New York and slightly less in Los Angeles. The two largest US cities are almost the most congested, according to data from the INRIX 2016 Traffic Scorecard. Smaller cities on the east and west coasts make up many of the other top congested cities. These include San Francisco, Boston, Miami, Washington and Seattle. Relative to its size, Chicago's congestion costs are low. Atlanta has relatively high costs, even though it's a smaller city. This would not be surprising for anyone who'd spent much time there. The Inrix survey includes many large cities with lower congestion costs per driver. These include Houston, Philadelphia, Pittsburgh and Detroit.
Inrix includes both direct and indirect costs in its calculations. Direct costs include the value of fuel and time wasted in congestion. Indirect costs include the increase in prices to households from freight trucks sitting in traffic. The top 10 most congested cities, as measured in cost per driver, are summarized in the bar mekko chart below:
I used pdftables to extract data from the Inrix report into an Excel workbook. I had to use an Excel formula to remove the $ before and the 'm' after the cost per driver numbers in the report. I then added population data for the cities that I found on another internet site. The bar mekko chart allowed me to contrast costs with city size in one chart. You can see that the two largest cities are also the most congested. After the top 2, many of the most congested cities are smaller (e.g., Atlanta and Miami).
In my bar mekko, I set the bar widths to be proportionate to city population and then included population as a data row. This is my standard approach when creating a bar mekko.
I made the following formatting changes to create the chart:
- removed the x and y axis (except for the y axis title)
- changed my color option to color by bar
- adjusted margins
- made all labels the same font size
- changed the y axis maximum to be close to 2.5
- slanted some of my bar labels to prevent them from overlapping
- adjusted some data row labels to fit under the slanted bar labels
- moved the y axis label to be level with the top bar total
Here is the chart in SlideShare to download and edit using Mekko Graphics.