The new Fairmount Street Bridge in Nashua is open to traffic, several weeks ahead of its target date and ending a period of detours around a portion of the city undergoing renewal as part of the Broad Street Parkway project. The 100-year-old-plus timber bridge that occupied the site was removed and a new, approximately $1.7 million concrete and steel span stretched over railroad tracks, and the new parkway that is nearing completion.