>how is it progressive, exactly?

Presumably rush hour commuters could afford more than others.

Maybe that's an incorrect assumption but if all we can do is time slice, I would expect rush hour commuters to have the most means.

Because professionals working full-time jobs and commuting at rush hour can typically afford the higher fare, while people working part-time/odd jobs/commuting to interviews/not working at all probably aren't the ones taking the rush hour trains.

Sure, there are some working poor who need to be in the office 9-5, but the majority of people working full time regular hours aren't poor. And for people who can't afford the increase, you just introduce an exception (if you make under $40,000 per year you don't pay the increased fare, or something like that)

You realise there’s a lot of people between wealthy professionals and part-time/odd job workers right? A secretary has to be on time, so does a cashier. I’m not sure what good peak pricing would do, apart from push them to less carbon-efficient forms of transport?

As long as the lines are still running at max capacity, you are still taking the same number of vehicles off the road. If you extend the period of max-capacity, you taking more cars off the road.

The question is if the benefit of more revenue and environmental savings warrants making the secretaries an cashiers adapt to less efficient schedules (eg come in earlier, stay later)

It's sad that making lower earners' lives even more difficult would even be a consideration in the first place.

Increasing capacity would also result in taking more vehicles off the road.

Increasing capacity can only be done with money, which needs to come from somewhere - most likely a tax increase elsewhere that will hit not only those same poor people, but also their neighbors who walk to work.

Peak fares to encourage people to work non-peak hours if possible can shift demand enough to mean you don't need build more transit now saving a lot of money now. Eventually there is no substitution for building more, but better utilization can ease that somewhat.

I agree that it is sad, but it is a real consideration. Nearly every environmental proposal has the potential increase hardship on low earners. Most commonly, this comes in the form of higher costs for consumer products, utilities, and housing.

There are are a lot of similarities with road congestion pricing going into effect in San Diego and NYC, and planned for LA and SF. Who will bear the greater burden, high earners who can easily pay the fee or low earners with rigid schedules.