The first phase of NYC's Second Avenue Subway line is scheduled to open in 2016.

It's the biggest expansion of the city's subway system in generations.

Last month, workers finished blasting work for Phase 1, which will run from 57th Street to 96th Street.

This is the site of a new station at 86th Street and Second Ave.

The new stations will be climate controlled, which is a big deal—temperatures on NYC subway platforms have been clocked at over 100 degrees Fahrenheit.

When the new line does open, it should ease crowding on the 4, 5, and 6 lines that now serve Manhattan's East Side.

And it will be easier to get around on the East Side in general.

The MTA expects the line to serve 200,000 daily riders when it opens.

But there's plenty of work left to do, including laying tracks.

And turning newly created caverns into something people will recognize at tunnels and stations.