by Michael Sivak, Sivak Applied Research.

In a recent analysis, I have shown that in March 2020 (the first month with the pandemic), the decrease in vehicle miles traveled (VMT) in the states with preference for Democrats was greater than in the states with preference for Republicans. The present analysis examined whether the pattern was still present in June 2020—the month with the most current available data.

According to the Federal Highway Administration, in June 2020, VMT decreased by 13.0% compared with June 2019. However, the decrease in VMT varied widely by state, ranging from 28.7% in Hawaii to 4.0% in Tennessee. Thus, this analysis examined the relationship between the decrease in VMT in June 2020 in individual states (and the District of Columbia) and whether those states were “blue” or “red.”

The data on political preference in June 2020 came from the Cook Political Report that was published on June 19, 2020. The Report lists each state as Solid Democrat, Likely Democrat, Lean Democrat, Toss Up, Lean Republican, Likely Republican, or Solid Republican. In the present analysis, the states were combined into three groups: Solid or Likely Democrat (N = 18), Lean Democrat, Toss Up, or Lean Republican (N = 13), and Likely or Solid Republican (N = 20).

The main result is that the average decrease in VMT in June 2020 in the states that were Solid or Likely Democrat was 17.7%, while in the states that were Solid or Likely Republican the decrease averaged 8.9%. In the Lean Democrat, Toss Up, or Lean Republican states, the decrease was in between—12.7%. (The analogous percentage decreases in March 2020 were 20.9%, 15.4%, and 16.8%, respectively.)

Although the states with preference for Democrats tend to be more urban than the states with preference for Republicans, the urban/rural difference does not fully account for the main finding. This is the case because in June 2020 VMT on urban roads decreased by 14.0% compared with a decrease of 10.7% on rural roads—a smaller difference than the Democrat/Republican difference obtained in this analysis.

Michael Sivak is the managing director of Sivak Applied Research and the former director of Sustainable Worldwide Transportation at the University of Michigan.