TomTom Traffic Index, Mobility, and Accessibility

For the past few years, TomTom has released a congestion report which profiles major cities in the world. The results are not surprising; cars can’t go the maximum speed limit during peak travel periods in major cities. The Province published an article on the report and used the sensational headline: “Gridlock! Vancouver has the worst congestion in Canada”.

When the first Traffic Index report was publish in 2012, I posted a critique on the study. I found that if free-flow traffic speeds are low, congestion delay will appear larger due to the way TomTom calculates their index. This is the case in Metro Vancouver.

The Traffic Index also doesn’t address walking, cycling, or transit which are important modes of travel in Metro Vancouver.

Todd Litman of the Victoria Transport Policy Institutes has written extensively on mobility and accessibility. Mobility is how fast you can get from point-a to point-b. Accessibility is the ease of “reaching goods, services, activities and destinations.” Litman argues that accessibility is what we should be focusing on, and that mobility is only one component of accessibility.

According to Litman, it is more important to build communities that have a variety of densities and land-uses that support putting people closer to the things they need like jobs and shopping. Building these types of communities also makes it easier to provide high-quality transit service while improving the walking and cycling experience.

Is it better to build a community so people can drive faster to a grocery store that is father away, or is it better to build a community that supports more grocery stores, so that people are closer to them? I support option B.

In fact Litman found that congestion may actually improve people's access to jobs, even if they drive.

A study that measured the number of jobs accessible by automobile within certain time periods for the 51 largest US metropolitan areas found that the five cities with the most intense congestion (highest Travel Time Index rating) are among the best for automobile employment access because their lower traffic speeds are more than offset by higher employment densities which reduce commute distances.

This is backed up by data from Stats Canada which showed that people's commute time actually dropped between 1992 and 2005 in Metro Vancouver.

The TomTom report is solely focused on the mobility of people travelling in an automobile. Methodology aside, the Time Travel Index completely ignores transit, cycling, and walking. An accessible region is a multi-modal region; Metro Vancouver is a multi-modal region. So while the TomTom report is good at generating headlines, it provides very little insight.

I do like the quote in the Province from the CEO of TomTom, “The traditional responses to congestion, such as building new roads or widening existing ones, are no longer proving to be effective.” In fact, the only way to reduce congestion is by using road pricing.