Mobility Drops 50% in Western U.S. Due to Wildfires

By Estelle Danilo, Flurry Analyst

Coronavirus has severely impacted U.S. mobility in 2020. Foot traffic to financial centers plunged by 70%. Trips to retail stores declined by 26%. Airport visits collapsed by 75%. And now with wildfires raging across much of the Western U.S., we see a new factor impacting mobility. With air quality critically impacted in California, Oregon and Washington, compounding a state of reduced mobility due to Coronavirus, we’ve seen an unprecedented reduction in people leaving their homes. In this report, we examine the impact of U.S. wildfires in the West on mobility through the usage of navigation apps.

Flurry Analytics, owned by Verizon Media, is used in over 1 million mobile applications, providing aggregated insights across more than 2 billion mobile devices per month. For this analysis, Flurry estimated user mobility using sessions across navigation mobile apps that provide drivers with directions, maps or speed meters. We also used the Air Quality Index from the U.S. Environmental Protection Agency. We focus this analysis on users in California, Oregon and Washington as these states have been most impacted by wildfires, as measured by the number of acres burnt.  

Using car trips measured across navigation apps we can see the shift in mobility. 

Fig. 1: Change in U.S. Navigation App Sessions during Wildfires

In the chart above, we show the daily percent change in navigation app sessions compared to a pre-wildfires baseline. We set the baseline to August 1 before wildfires grew severe enough to become a U.S. trending topic, according to Google Trends. Since observed changes were similar across California, Oregon and Washington, we present their group average in the chart. The color of the dots across the line represents the air quality measured on that day. For instance, the August 1 data point is green because air quality was considered “good” while the September 14 data point is red because it measured “very unhealthy” on that day.

On September 11, for the first time in 2020, air quality was considered “unhealthy” across California, Oregon and Washington. Over the next 3 days, air quality grew “very unhealthy,” resulting in navigation app sessions dropping by a staggering 55%. Similar but less severe drops also occurred when air quality worsened from “good” to “moderate” on both August 20 and September 5. Navigation apps reached their lowest point on September 19 following seven straight days of “unhealthy” to “very unhealthy” levels.  As air quality dropped, so too did mobile trips outside the home. More recently, while air quality has come back to healthy levels in Oregon and Washington, moderate air quality persists in California, resulting in depressed mobility.

Due to poor air quality from wildfires, user mobility has dropped by 50% on average across California, Oregon and Washington. With new wildfires such as Zogg and Glass spreading in California as of September 27, the west coast is not yet back to normal. We’ll keep you updated on future important trends in travel and mobility. For the latest reports, subscribe to the Flurry Analytics blog and follow us on Twitter and LinkedIn to get the latest industry analyses.