Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Assembly Square is a planned stop on the MBTA's Orange Line. The station is scheduled to open in 2013. It is being built alongside the planned Assembly Square project. The station will consist of a single island platform 410 feet long. Unlike the surrounding stations, Assembly Square will not have a second island platform to serve the third track, which was originally intended to be an express track. The station will have two headhouses, one on each end of the platform.