How effective do they expect a measure like this to be? Once a car and its insurance are paid for, the marginal cost of a single trip is quite low. I seriously wonder how many people woke up that day and thought "instead of driving I will take the train today because they are waiving the $3 fee" not many I bet. If we want to encourage people to take public transports we need to keep them competitive against the car at all times not one random week per year.

Maybe you don't see it, but many folks would value the pro-social benefit as being worth more than the marginal costs of driving a car. Like, for instance, if you're living through a spike in pollution, you may be motivated to do your part to help.

It might be enough to get someone to try transit and see that it actually does work. If you are used to driving everywhere and have never used transit then you won't actually know how it works. Routes, timing, transfers, missing the bus... - there are a lot of things that are different about using transit, none of it hard, but all of it needs to be learned. Free transit may be enough to get you to try it once (exactly once!), and if transit works that will be enough that you become willing to figure out how to buy the fare in the future.

In general free transit is a bad idea - nearly everybody is willing to pay a small fee for transit and what they really want is better service (better service meaning more routes, faster routes, and more frequent - pick as many as possible)

The $3 -> wouldn't motivate a lot of people, it's more like the cherry on top of asking folks nicely to drive less.

Like if you asked me to help you move a couch and offered me a beer, a beer isn't really a fair trade for the labor value, but I'm being nice and helping, a nice treat makes things a little better.

I think there is also a PR factor beyond the market economics of the $3 discount. Announcing the free transit alongside the pollution spike will get more people to read about it and consider whether they should make the choice to help with the pollution spike by taking transit.

There is also a bigger difference between free and $3 than between $3 and $6. Free means you don't have to buy a ticket, deal with the app or ticket machine, or have an existing public transit card. The "power of free" is worth considering here.

We often think of everyday behavior in terms of cost-benefit, but that's not all it is. Waiving the fee is a signal to indicate that taking public transit is socially desirable. That could be an effective nudge for many who are indecisive.

When I actually calculate the gas cost for a trip in a car, I am usually surprised at how large it can be. I wouldn’t be surprised if the $3 actually is less than the gas cost for many affected commutes.

However I think you are probably right that it won’t make much difference for a single week, since I think people tend to ignore this cost. Filling up the tank is infrequent enough and part of a routine that imo it doesn’t feel like a marginal cost and feels more like a fixed cost of car ownership

Cultural differences. Think of pandemic days, and how each country/city operated. Despite having almost no official lockdowns, Tokyo operated in self-induced lockdown style as people didn’t really want to exacerbate the problem. It was kind of the opposite in other places.

People in Switzerland might consider other things as the main goal (making the air cleaner), and this could be a simple nudge to change their behaviours. It’s not always monetary competitiveness that shapes behaviour.