N.H. Rev. Stat. Ann. § 243:42

No corporation shall locate a railroad upon or over any portion of a route for which a charter of any other corporation was upon September 14, 1883, and still is, existing, and under which a location has not been made, until it has been made or until the time limited in the charter for the location has expired; and no corporation shall locate a railroad upon or over any portion of a location made by any other corporation, except so far as may be necessary for connections and crossings.