D.C.'s busiest Metro station and number-one tourist attraction (measured by out-of-towners' foot traffic) is prepping for a huge change.

The station, which also is one of the biggest Amtrak stations in the country, estimates that ridership will triple in the next three decades. That's a lot of people. 

To prepare for this enormous shift in thinking, station stakeholders have designed the Union Station Master Plan, which calls for doubling the train capacity and tripling passenger capacity, improving the station experience for visitors and making it a more integrated part of the neighborhood.

Union Station will be a place to watch carefully in the years to come, as the planned construction has the potential to drastically transform the neighborhood.