February 11, 2021

How do Americans combine ridehailing with other modes?

There is ongoing interest in how people use ridehailing services like Uber and Lyft: what modes they replace; what purposes they serve; how they interact with transit. In a new paper in the journal Transportation, Sustainable Transportation Lab alum and current UC Davis PhD student Summer Wu and I look specifically at how travelers link ridehailing services with other modes in the course of a multi-stop tour, using the representative samples of the U.S. National Household Travel Surveys from 2001, 2009, and 2017.

First, a caveat: Although the NHTS provides a representative look at US travel patterns, an important limitation is that it does not distinguish between taxis and ridehailing services. So in our work, we combine these services together. Nevertheless, it is likely that essentially all growth in this segment between 2009 and 2017 is due to ridehailing services.

We began by dividing trip purposes (activities at destinations) into a few main types:

• Home activities only take place at home location;
• Mandatory activities are things like work and school, where you have to be at a specific place at a specific time;
• Flexible activities are things you have to do, but which have flexibility in timing;
• Optional activities are things like recreation and visiting friends);
• Mode transfer includes trips made specifically for the purpose of connecting to another transportation mode (only recorded in the 2017 survey).

Consistent with other research, we find that the most common use of ridehailing services is a late night trip home from optional activities. Somewhat surprisingly, we found that the second largest share of trips was morning trips from home to mandatory destinations, suggesting that taxis and ridehailing are being used as a commute mode to reach work and school. An even larger number of trips are people returning home from these activities, though the demand is spread more widely across the afternoon, evening, and late night hours.

Next, we looked at the types of tours that include ridehailing for at least one trip:

• Simple tours go from home to one destination type and back again. The destination may be mandatory, optional, or flexible.
• Complex mandatory tours include multiple non-home destinations, including at least one mandatory activity.
• Complex non-mandatory tours include multiple optional and/or flexible activities, but no mandatory activities.

We looked at the growth in tour types involving taxis or ridehailing, and found that the fastest relative growth was in simple mandatory tours (again, meaning home to work/school and back), which increased their share of all taxi/ridehailing tours by 70% between 2009 and 2017.

Finally, we looked at the interactions between transit and taxi/ridehailing services. Although Uber and Lyft are fond of pointing out that 25-30% of their trips start or end near a transit station, we found that less than 1% of taxi/ridehailing trips in the NHTS were used for a direct connection to or from transit. This suggests that Uber and Lyft’s numbers are more about correlation between common origin and destination locations than about ridehailing being used as a first/last mile service. Nevertheless, we also found that about 1/3 of all tours that include taxi/ridehailing also include transit. And, we saw an increase in the overall share of monomodal biking, walking, and transit tours, suggesting a broad complementarity between ridehailing and these modes.

There’s lots more in the full paper. Interested readers can find a non-paywalled version of the accepted manuscript here.