Grantee of this franchise shall relocate, without expense to city, any pipes and appurtenances theretofore installed, and then maintained or used under this franchise, if and when made necessary by any lawful change of grade, alignment or width of any streets by city, including the construction of any subway or viaduct; provided, however, that the cost of any such relocation made necessary by the construction or any lawful change of grade, alignment or width of any freeway constructed by the state of California shall be divided equally between grantee and the state of California. (Prior code § 10-26)