Traffic congestion is caused by many factors: population and employment growth, construction activity, deliveries, on-street parking, aggressive lane-shifting drivers, and more.

But, policy makers insist that Uber and Lyft are the primary culprits. This belief has led officials in New York City and elsewhere to propose caps on the number of rideshare vehicles,  in the name of taming congestion. 

READING THE POLLS:

Sometimes policy makers take the polls too seriously or over-interpret the results. An oft-cited poll of rideshare users in Boston, Ma. cites that 42 percent of rideshare users would otherwise use public transit. A 2017 UC Davis study of Lyft and Uber riders in seven major cities reports that fifteen percent said they would ride transit more if ride-hailing was no longer available. A separate  poll in Boston observes that 30 percent of riders have switched from transit to rideshare.  

If you unpack the surveys, there are red flags:

1. When riders take a poll (i.e. survey) they seek a response which is socially correct and appears reasonable. It is less socially acceptable to say you would use your own vehicle and drive…it is more socially acceptable to say you would have taken the bus or train.                                                                                                                                                   
2. Some polls fail to report the number of riders who do not currently own a car, or who have decided to postpone the purchase of one.                                                                                                                       
3.  In most major cities, public transit operates at capacity during peak commute hours. Young people have accelerated the demand for transit because they have a lower rate of car-ownership and live close in. However, transit capacity has not expanded to meet the ridership growth.                                                                                                               
4. Under real conditions, riders may not take the bus or train on consecutive days of the work week. The decision to ride transit on a particular day depends on multiple factors: weather, if there are kids to pick up or drop off, packages or heavy bags to tote, and the walking distance to and from the bus stop.

INFERENCES:

It is both a statistical error and a social one to infer that all of the people who said they would have used mass transit would have completed their trip that way.

There is recent data from rideshare studies that inform the issue. One of the largest increases in rideshare takes place during late evenings and weekends… times when transit service is less frequent and there are longer waits. On weekends and evenings, car owners find rideshare to be convenient for other reasons too. They can save on the cost of parking, and not worry about DUI’s.

SURVEYS ARE SIMPLE:

The thing to keep in mind is that surveys are simple…but trips are not. If someone decides to drive, instead of taking Uber or Lyft, they might “bundle” the reason for taking that trip with other interim stops. These are called “chained trips” and drivers typically complete multiple stops (or errands) on a single tour. A survey question about a single trip does not get at the nuances of chained travel, and when you ask people specifically about a single transport mode they don’t tell you why they are traveling.

The demand for trip taking is elastic, so adding capacity will encourage brand new activity patterns and travel. The convenience, reliability and low cost of rideshare has surely increased trip taking.  This observation is highlighted  in the op cit. Clewlow/Misha/UC Davis poll: 22 % say they would take fewer trips without rideshare.

NEW PLATFORM= NEW DEMAND:

However, turned around, new travel trips would also have occurred on a different platform… say public transit…if transit had become more convenient, frequent, and reliable. Unfortunately, it has not kept pace with the return of Millennials to cities and most urban systems are hobbled by network and capacity issues. The gain in more personal travel modes, like bicycles and scooters is probably indicative of underlying demand. However, these modes are not safe or practical for many potential users.  Uber and Lyft have taken up the slack.

It’s easy to point to survey results that favor transit and to scapegoat rideshare for slowing down traffic. It’s also easy for lawmakers to then proceed from survey result “A” to outcome “B” and advocacy “C”: namely, a tax or freeze on rideshare in the spirit of trying to rein it in. It is a remnant from the heady days of selling taxi medallions.

It’s harder for these survey pundits to admit that cracks in the existing transit system enabled the demand for more travel trips and hence rideshare… to spring up.