More on Declining Transit Ridership

Bern Grush wrote in about my last post (on transit decline) to say:

There is a third contributor. Marchetti, in his 1994 classic: “Anthropological invariants in Travel Behavior”, wrote: “…People spend about 13% of their disposable income on traveling. The percentage is the same in Germany or Canada, now or in 1930. Within this budget, time and money are allocated between the various modes of transport available to the traveler in such a way as to maximize mean speed. The very poor man walks and makes 5 km/day, the very rich man flies and makes 500 km/day. The rest sit in between. People owning a car use it far about one hour a day (Figure 12) and travel about 50 km/day (Figure 13). People who do not have a car spend less than 13% of their disposable income, however, presumably because public services are underrated and consequently there is no possibility of spending that share of income traveling one hour per day (Figure 14).”

What this means is that there is a heretofore unexploited opportunity gap between those just wealthy enough to {own, maintain, fuel, park}  a car and those just poor enough not to (and hence do not have a car). This car-less gap would include a lot of people who would be spending far under their nominal 13%, and could afford one or more weekly substitutions of a TNC ride for a transit ride.  As TNCs grow this market will move some of the people in the gap of that bimodal distribution from transit to TNCs.

I think this explains some of Bruce Schaller’s NYC taxi-report.

Someone else also noted TNCs (Transportation Network Companies like Uber/Lyft etc.).

While I think there is something to travel budgets (and credit Zahavi before Marchetti), they are not too rigid, clearly time spent traveling ebbs and flows (Wei and Song 2016).

I also think TNCs are too small a factor at this stage of history to explain much. As I wrote before, their market share is still pretty small, even in New York City, where presumably is its largest, and the drop in transit ridership is far more than the switch to TNC trips from transit users.