The sudden decline in travel due to fear of Covid-19 is obviously affecting public transit. Preliminary and unpublished numbers shared with me by two US West Coast agencies showed ridership losses of 30-50% from pre-crisis levels. We’ll see plenty of published numbers soon. The sudden fall in gas prices at the same time could make the ridership impacts even worse.

This is a good time to remind ourselves, and our favorite journalists, that ridership is always volatile and heavily driven by factors outside an agency’s control. There are many things transit agencies can work on to improve ridership, but (a) those things together amount to a minority of the total forces governing ridership and (b) ridership isn’t the sole metric of success for transit agencies, and sometimes not even a predominant one.

However, transit agencies can do things that will cause ridership to fall further and stay down longer: They can cut service, as they will be tempted to do now.

It’s not hard to see the dangers:

Declining fare revenue, due to lower ridership.

Declining tax revenue, due to economic slowdown.[1]

So what should transit agencies do if they start to run out of money? Cut service? If so, how?

First, let’s distinguish between service and capacity. If revenue falls, many urban transit agencies can trim rush hour capacity without affecting customer mobility very much. If you’re running a commuter bus every 7 minutes at rush hour, cut that to 10 or 12 or whatever the loads support. Because peak commuters mostly plan around the schedule, the impact on travel time is trivial, but you’ll save something. Peak-only service is very expensive, so you can save a lot by trimming that. What’s more, preliminary numbers I’ve seen show commute ridership falling much more steeply than all-day local ridership, which suggests that the peak should bear the brunt of any temporary service cuts.

By contrast, when you start cutting all-day and all-week service, by reducing frequencies, you start to dramatically reduce the usefulness of network, and this is the most efficient way to drive riders away. You also trigger social justice impacts, because lower income riders tend to be all-day, evening, and weekend riders, not just peak riders.

Remember, the riders you drive away due to service cuts will stay gone until the service improves again, while those who are just working from home will come back post-crisis if the service is still there.

Second, if money runs low, you have to question the schedules of your infrastructure projects.

Infrastructure projects are so complicated and involve so many possible points of failure that they require a concerted effort to maintain momentum. All the messaging around how inevitable the project is, and how certain the opening day is, can make it sound like nothing can be slowed down in response to a crisis. Of course, some contracts do impose costs for slowing and stopping, and those have to be considered.

But if infrastructure work continues while service is being cut, you’re driving away current riders for the sake of future riders, and if the goal is ridership, that makes no sense. It can also be a social justice problem.

Why do I have to point these things out? Influential people often tend to be peak commuters, so they defend peak service but care less about all-day service. They also tend to be invested in infrastructure, and don’t want to hear that those projects might have to slow down. To many of them, all-day service can seems easy to cut by comparison, since that affects people who don’t comment as much. But apart from trimming peak capacity, that’s the sure way to turn a temporary crisis into a more lasting one.

[1] These impacts will be cushioned if agencies have (a) a lot of pre-sold fares, such as employer programs and (b) tax sources that rely on less-volatile sources like property or income tax, as opposed to payroll or sales taxes.