Section 1. In this chapter, unless the context otherwise requires, the ”department” means the department of public utilities. An ”interested party”, in any proceeding under this chapter before the department, the board of aldermen of any city or the selectmen of any town, shall include any person whose land is to be taken or whose estate abuts upon any highway through which the electric railroad is to pass, and any railroad corporation or street railway company having a location in any city or town included within the proposed route of the electric railroad company.