Paul May


30 December 2011

In 2011, Genevieve Hoffman, Stepan Boltalin and I proposed MetroChange, a micro-donation platform that would allow users of the New York City transit systems to donate the small amounts of remaining value on their Metrocards to charity.

When the project started, we knew (anecdotally) that it was common for Metrocards to be discarded with small amounts of remaining value. We wondered what this waste meant at scale, and what factors in the design of the Metrocard system lead to waste.

We tackled this project from a number of different angles.

We did cent by cent analysis of the NYC subway fare system, and an evaluation of the HCI of Metrocard vending machines. We saw that some price points highlighted for “quick purchase” in the Metrocard vending machine UI resulted in the most amount of wasted value on Metrocards. We found a reliable source that estimated the value of waste left on discarded Metrocards at over $50m each year.

Spurred on by these findings, we proposed an alternative to this waste; a micro-donation service that would see remaining value diverted to charities.

We built a magnetic card reader capable of decoding the data stored New York City Metrocards, including the remaining value stored on the card in dollars and cents. Technically, this was very challenging, since the physical design of Metrocards differs from many magnetic stripe designs. We built prototype after prototype, until we had a working system.

We brought a fully working Metrochange kiosk out onto the streets of New York, and tested it with passers by. We met with city officials to discuss the project, as well as potential charity parters. The project received widespread press coverage, and prompted a real conversation about the design of the Metrocard system.

Ultimately, we recognized that there was no way the MTA would agree to donate or divert $50m of revenue, but we had a lot of fun posing the question.

Project Images

The MetroChange kiosk
The value of the card is read, and added to a total value. The user is asked to discard their Metrocard for recycling.
Inside the MetroChange kiosk.
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  • Paul May is a researcher, interaction designer, and technologist from Dublin, Ireland. He is currently working with Memorial Sloan Kettering Cancer Center on smart health applications.