Trips towards Williamsburg will soon be a little less cramped. In two days the Metropolitan Transportation Authority will add seven round-trip trains on Sundays, 16 peak and off-peak round-trip trains on weekdays, and 11 round-trip trains on Saturdays, according to State Senator Daniel Squadron. It was Mr. Squadron who pressed for the increased service last year following the release of a study that found a “meteoric” increase in ridership along the L. He’ll officially commemorate the new L trains on Monday at the Bedford Avenue stop.