Transit statistics are complicated and can be misleading

[Matthew H Fish]

This is a question I have had for a while, that seems to come up whenever I am in a discussion trying to compare transit systems across cities. This applies for train based transit, and also for bus based transit (or even for ferry transit, where applicable). There are many types of transit, and even with trains, we have streetcars/light rail/subways and metros/commuter rail/corridor rail/long distance transit. These systems are designed in different times and different places, and sometimes a city will have a legacy system that functions differently than when it was designed.
Speaking of cities, for the most part, cities don't run transit, transit agencies do, and they usually are based on a metro area. Determining the population of a metro area is difficult, because a transit system might not cover all of a statistical metro area, or it might go outside of its metro area, or both.
It is also hard to know how much use a transit system gets. Because trips can be measured by unlinked trips, or by total trip. But the first can be deceptive, because an inefficient transit system is going to have "more trips"--- if someone has to go to a hub and take another trip, that is going to count as two trips, whereas a direct trip will be only one. Passenger miles can also be deceptive, because different types of systems naturally have different numbers of riders. The Long Island Railroad has 1200 riders per mile, the Kansas City Streetcar has 2600. But the LIRR is a major commuter rail line, the Kansas City Streetcar has 2 miles of tourist-oriented track.
So say I want to ask a question like "How does Salt Lake City compare to Cleveland as far as transit ridership?" First you have to determine what you mean by "Salt Lake City" and "Cleveland". At least one part of the SLC transit system, the FrontRunner commuter rail, goes outside of the official SLC region. On the other hand, the Cleveland transit system, apparently, is confined to just one county. So how do you compare the region's populations? How do you compare commuter rail to light rail?
This isn't just an academic question: it is important when evaluating how well a transit system is doing. A light rail system that has many suburban routes might be getting a third less riders per mile than a streetcar system that only serves an urban core, so it is not accurate to compare them. And it isn't always easy to tell the difference between a light rail line and a streetcar line. So is there any standardized way to look at rail and transit statistics?

 

[Willbridge]

There have been lots of attempts, but there are problems with all of them. A common device is to compare "peer" systems rather than comparing a system against all others. That still can be muddied by choosing peers that are the same size organization, but in different size markets. Or the opposite by choosing peers that are the same size market, but different size organizations.

The National Transit Database attempts to standardize data, but users are left to draw their own conclusions. And that still doesn't help when Canadian systems are brought into discussions.

https://www.transit.dot.gov/ntd
Some people try to use the American Community Survey information combined with GIS transit route maps. This only works on a large geographic area, but that hasn't stopped efforts to get details:
https://en.wikipedia.org/wiki/American_Community_Survey
Here's an example of using the ACS:
https://en.wikipedia.org/wiki/List_...33.7% 5. San Francisco, California – 33.1% 6.
Here's a look at how the industry trade association sees it:
https://www.apta.com/research-technical-resources/transit-statistics/ridership-report/
A sidelight on these statistics: when I was working with trolley coach issues there were some predictable fallacious statistics used to "prove" that they were more costly than Diesels. But when I looked up system level data there was no difference between the systems that had trolley coaches and peer systems which did not have them.

 

[west point]

A sidelight on these statistics: when I was working with trolley coach issues there were some predictable fallacious statistics used to "prove" that they were more costly than Diesels. But when I looked up system level data there was no difference between the systems that had trolley coaches and peer systems which did not have them.

That happened in the 1960s in Atlanta. Atlanta transit system needed to replac ageing TTs. GM claimed that there new window diesel operations would be less than electric busses. Was not as expenses went above TTs after about a year. Mainly the salvage value of the copper contact wire and transmission wire was the only quick value of switching.