Car Lite San Mateo

Cars and Household Growth in San Mateo

Overview

There was an analysis of census data related to car ownership in Seattle making the rounds a few weeks ago. This data showed that despite growth in number of residents in Seattle the number of cars held mostly steady since 2017. I was inspired by a similar analysis of Madison, WI and got curious about these trends in San Mateo, CA.

San Mateo Data

I plotted out a slightly longer term look at the number of cars in San Mateo, CA

Cars in San Mateo

We see much less of a clear trend. There is a rise from 2007-2010, a fall from 2010-2012, another rise leading up to Covid-19 and then a general downward trend spanning the missing data year of 2020 during Covid-19. Post 2020 there is a big jump to the overall maximum in 2023.

Households in San Mateo

This is a generally similar plot with the same minimum and maximum points in 2007 and 2023. At a high level it matches the shape and the cars per 100 households tells a similar story.

Cars per 100 Households in San Mateo

Still Lots of Cars

Despite lots of changes in San Mateo we haven't figured out a formula to add households to our city without adding ~1.8 cars. For comparison the analysis of Madison, WI linked above showed a general downward trend from ~1.5 to ~1.4 cars per household throughout this time frame. Recent trends of more housing near transit will hopefully show some better results in the near future!

How Car Bloat Plays a Role

These modest changes didn't match what I've heard from residents and seen myself living in the city. San Mateo, CA had its peak number of cars in 2023 and its minimum in 2007. I was curious what could be learned looking at the size of the Top 10 cars from these two years and how that might also contribute to the general "Why are there cars everywhere" feeling.

Since this is getting long, I'll dig into this in another post on San Mateo car bloat.

Data Sources

All of the household and number of car data in the initial analysis comes from 1-year American Community Survey Census data. These are detailed datasets that are amazing to understand trends and changes over time. There are lots of ways to get access to this data from the official US Census Bureau using their APIs and datasets.