The Metropolitan Transportation Authority unveiled its first mobile ticketing app Tuesday, which will riders on Metro North and Long Island Rail Road to purchase tickets using their smartphones by the end of summer 2016. The MTA eTix app is available for both iOS and Android users. It already is operational for riders of Metro North’s Hudson line, which runs north from New York City’s Grand Central Terminal along the Hudson River, and LIRR’s Port Washington branch, which runs east from Penn Station.

Previously, the MTA said that e-ticketing for its commuter rail lines wouldn’t be available until the end of 2016, making today’s announcement a welcome sign of progress for the ongoing effort to upgrade and modernize the nation’s largest public transit system.

While this is good news for the 86.1 million people who use Metro North and 87.6 million people who ride LIRR every year, it won’t have much effect for the 1.76 billion people who ride the New York City subway system . That’s because the MTA is only now looking for a contractor to install a mobile ticketing system for the subway. After it picks a vendor, the MTA says the contract will have a duration of 69 months, which means it won't be up and running until at least 2021. And given the MTA's track record for completing projects on time, probably even later than that.

“puts riders first by eliminating the ticket line”

New York Governor Andrew Cuomo, who controls the MTA, seems like he’s trying to squash the perception that major transit improvements need to happen as slowly as possible. In a statement, he said the new app “puts riders first by eliminating the ticket line and helping New Yorkers and visitors get where they need to go with more freedom and convenience than ever before.”

The MTA decided to adopt the more aggressive roll-out schedule after a successful field test, in which 150 riders used the app to pay for trips. Ninety-two percent said they were satisfied with the experience, and 94 percent they would use the app when it was publicly available.

One reason why the MTA is able to roll out mobile payments faster for Metro North and LIRR, and not for the subway, is that tickets for commuter rail are still checked by human conductors. An e-ticket system for the subway will require massive, expensive infrastructure changes, such as retrofitting the turnstiles at all 469 stations.

The MTA’s eTix app was developed by Massachusetts-based mobile-ticketing firm Masabi, which is expected to put in a bid to create the new fare system for the subway. A successful roll-out for Metro North and LIRR could give it a leg up in the competition.