I write about transit at times here; it’s generally top of mind for me given my regular commuting. But a number of subway-related links have fallen into my drafts folder over the past few months, so for the time being Sundays are going to be dubbed “Subway Sundays” and I’ll be sharing some cool stuff around it.

This week’s post revolves around the unnecessarily complex math that has sometimes been needed to zero out a MetroCard, which is used to pay for subway rides. Fares are generally round enough – until last week they were $2.50, and just increased to $2.75 – but when you put money on your card, bonuses are also applied which don’t always line up.

During the previous fare hike, for that $2.50 fare, the bonus when you put a certain amount or more of money on your card was 5%. That made the math easy – for every $50 you put on your card, you got an extra $2.50 – effectively an extra ride. With the new $2.75 fare hike, the bonus is an 11% bonus. The not-so-round fare plus the no-so-round bonus creates a bit more difficulty in figuring out how to ultimately bring your MetroCard down to zero.

During the previous go-around, website I Quant NY pushed the MTA to get more creative. The number $19.05 was also thrown out as a way to help people round their MetroCard off, but that number no longer works with the new fares. Thanksfully, the MTA heeded the call and did two things to simplify the problem.

A MetroCard calculator was introduced to help you figure out what to deposit. Type in what you have, and how much you’re planning to add, and it’ll not only tell you where you’d land with your deposit and bonus, it’ll also suggest other numbers that will let you reach zero.

Photo via iQuantNY

But that only works if you’re thinking about it before leaving home, and you remember how much you had to begin with. So to assist further, another button has been added to the MetroCard that will let you also buy a MetroCard that’s been calculated to be an exact number of rides.

For most riders, who refill all the time, this may not be important, which Ben Kabak rightly notes on Second Avenue Sagas, but as it turns out, the MTA ends up sitting on a lot of small, unused leftovers. When the numbers get crazy like this, it improves their ability to be able to sit on extra money, which, given card expiration dates and the like, opens up the chance for them to pick up extra money because of the awkward math. Before I truly understood how that all worked, I had a few cards with a small amount of leftovers that expired on me as well. I’m not going to miss that $1.25, but the MTA gets to add it to their pool.

Kudos to I Quant NY for pushing for the change, and for the rest of us, we can now ensure that our money is fully utilized. There’s still work that can be done – the button on the machine doesn’t clearly tell you that is the purpose of that odd looking amount – but at least it exists now, and those of us seeking it now have an option.