Credit: Electrek

Photo: Amelia Holowaty Krales / The Verge
Photo: Amelia Holowaty Krales / The Verge

I think my parents are a relevant case study here. My dad drives a Chevy Bolt (an EV); my mom drives a small SUV. When they go on longer trips (such as to their friend’s house on an unpaved road several hundred miles away), they take the SUV. So, they’re a perfect example of this phenomenon in practice — even though my dad owns the EV, some of his vehicle miles are shifted to the SUV, which has higher emissions.

So… should we worry about this? Well, I think that some of this impact is likely to be temporary. The primary reasons my parents opt not to use the EV, for example, is 1) seat comfort, 2) 4-wheel drive, and 3) vehicle range. As manufacturers release larger, more comfortable electric vehicles, with longer ranges, it is plausible that the gaps in driving behavior shrink substantially.

And of course, there are multiple perspectives here: a group from the UC Davis Institute of Transportation Studies presents data, which argues that electric vehicles have pretty similar usage patterns to gas cars. Analysis that primarily leverages home electricity usage data seems to show the cars are driven less, while analysis primarily using survey data tends to show they are driven at similar rates (but may suffer from reporting bias from people who are excited to talk about their new car). The authors of the EPIC study (who are also affiliated with the Energy Institute at Haas Business School) also followed up to provide more context and respond to questions about the original research.

My personal (data-free) intuition is that the EPIC study is probably a pretty good estimate — and that EVs purchased between 2014 and 2017 are being driven less than their gas counterparts. At the same time, I would guess that as the authors of the EPIC study update this work with newer vehicle data (say, vehicles purchased in the last couple of years), that this gap will shrink (but not disappear altogether).