[afuchs]

> ... It feels like there could be some societal benefit to similarly reducing the number of busses and just making them free. (Today most busses are only at 10-30% capacity). ...

Public transit systems need to consider a lot of trade offs when they plan how to use the resources they have.

Optimizing for cost like this can make the busses less practical to use and less attractive to potential riders.

If a bus stop is only visited by a bus once an hour, then the average amount of time someone needs to wait for a bus to visit that bus stop is 30 minutes (assuming a uniform distribution for when that person arrives at the bus stop). If the bus stop is visited by a bus every 20 minutes, then that person would only need to wait at that bus stop for an average of 10 minutes.

The average time of a trip on this bus will be roughly equal to: the time to walk to the bus stop + the time spent waiting for the bus + the time the bus takes to reach the closest stop to the destination + the time to walk to the destination.

From that, reducing the number of busses that visit that bus stop increases the average amount of time for trips which originate from that bus stop.

A factor which impacts usage of public transit system is how quickly it can get someone to some arbitrary destination.

So, cutting the amount of busses a public transit system runs can reduce costs but also reduces how attractive that public transit system is to potential riders because of the increase in the amount of time an average trip takes.

That increases the use of other forms of transportation, assuming that people don't forgo trips entirely (e.g., staying home instead of going to a bar and getting a DUI, or eating at a hotel's restaurant to avoid spending $60-80 on taxis or Uber for a single meal).