Soon, you won’t have to use these. Photo by MattHurst on Flickr.

WMATA is rolling out the latest upgrade to the SmarTrip website, letting riders add money or passes to their cards online instead of having to go to the vending machines in stations.

The new feature is currently a pilot for 5,000 users, including 50 who asked to be included over Twitter. If all goes well, WMATA hopes to release it to everyone in a month, said spokesperson Dan Stessel.

Those with the feature enabled can log in to an existing account or, if they don’t have one, register their SmarTrip card. Even if you don’t have the feature, it’s useful to set up an account to see your balance and get protection against losing your card.

Once users log in, those with the feature have a new link to add value, taking them to this screen:

Click to enlarge.

The site lets riders add between $10 and $200 in cash to the card, or add the 7-day bus pass. In the future, Metro will have additional passes for purchase including ones for other transit systems like Maryland MTA, PRTC, and more.

Because of the way the SmarTrips work, adding money to the card doesn’t instantly update the card balance. SmarTrip cards store their value directly on the card, encoded on the card’s chips. If you add $20 to your card online, WMATA’s central servers know you added it, but the card doesn’t yet since it can’t communicate with the servers when it’s in your pocket.

To update the card, you have to touch the card to one of the targets on a bus or rail faregate. Those targets all get a periodic download of all the transactions. When it sees your card, if it has a transaction in its memory for your card, it will add the value to your card.

It takes some time for all the transactions to get to the targets. The rail ones are wired into a network and get downloads periodically throughout the day, but can take up to 1 day to get them. The bus ones have to be updated when the bus is in the depot, so it can take an extra day.

The bottom line is that some people might add $20 to their card, then go to a rail station or bus soon after and get confused when their card doesn’t yet reflect the added money.

In the long run, WMATA wants to switch to a different system that’s more like your debit card: the balance is actually in a central database, not on the card, and when you swipe it, the terminal communicates with the credit card company to check your balance.

However, that takes some time, which is why credit card terminals have some delay. To let people touch their card to a faregate and go through right away, WMATA has to make sure this communication happens very quickly.

They also want to integrate it with credit cards that have built-in chips; it’s possible you could just tap your credit card instead of a SmarTrip one day and have it charge your card for the ride, or charge you at the end of the month for all of your rides that month.

There’s an RFP out now to design this system. Kurt Raschke has analyzed some of the technical details, and we’re working on an explanation that’ll be more accessible to those not familiar with payment industry jargon.

In the meantime, WMATA is working on additional upgrades to the SmarTrip site including the ability to enter a credit card and have it automatically reload your card when the balance gets low, like you can do today with E-ZPass.

Disclosure: I met with the site designers recently to give feedback on usability, such as layout of items, explanatory text, and more. A number of modifications based on my suggestions as well as others they thought of are reflected in the current interface.

David Alpert is Founder and President of Greater Greater Washington and Executive Director of DC Surface Transit. He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He lives with his wife and two children in Dupont Circle. Unless otherwise noted, opinions here are his and not the official views of GGWash or DCST.