Sustainable Transportation Lab

August 4, 2016

Long-term impacts of new mobility services

Don MacKenzie

Don MacKenzie

The Sustainable Transportation Lab is conducting a major study of new mobility services in partnership with the ridesharing company Lyft and BMW’s on-demand carsharing service ReachNow. The objective of the study – being driven by the tenacious leadership of visiting PhD candidate Michiko Namazu – is to identify how new mobility services affect key sustainability indicators over the long term. (Acknowledging that they are new mobility services, so the long term does not exist quite yet.)

Full disclosure: As an individual, I personally use Lyft on a regular basis and love it, and ReachNow has become my first stop for free-float carsharing, mainly because it’s an excuse to drive an i3 electric vehicle. As a researcher, understanding how these services are expanding transportation options and changing behaviors poses a host of fascinating questions. So I was pleased that the companies were willing to work with the Sustainable Transportation Lab on this study.

It is well established that people who use new mobility services travel differently than those who don’t. The big question – which we are addressing in this study – is all about causality. We know that to a certain extent, the kind of people who choose to make carsharing and ridesourcing a part of their transportation mix are just plain different than the people who don’t. But, once you start using these services, your behavior can change as well – maybe you realize that you can take the bus to work and still have a convenient, quick, and safe ride home after happy hour; maybe you don’t need that second car any more, or any car at all; and suddenly you can choose a place to live without worrying about where you’ll park the car(s).

The key unknown is how much of the overall difference in behavior is due to these underlying differences versus changes caused by using new mobility services. Most of what we know about carsharing and ridesourcing comes (unsurprisingly) from studying carsharing and ridesourcing users. This is a natural place to start, but it makes it hard to address the “what if” question of how these people would be traveling if they weren’t carshare members or ridesourcing users. Other researchers have been digging into this, but what’s different about our study is our experimental approach: offering incentives to nudge some people into using these services, and then comparing them with people who didn’t get the nudge. This is called a randomized encouragement experiment, and if all goes well, it will allow us to see how new mobility services cause travel mode choices, vehicle ownership, and even residential location to evolve over time.

This is an exciting study, one we have been cooking up for some time now, and the wide range of mobility options in Seattle makes our city a great place to run this experiment. We’re lucky to have committed partners in Lyft and ReachNow, who are providing the incentives for our participants to trial their services – something that would be costly and difficult for us to do on our own. I look forward seeing how this work turns out, and to sharing the results here.