When it shall be necessary to advertise for bids to build and construct a viaduct or bridge, the board or boards of chosen freeholders shall, before advertising therefor, determine the kind, style and design (one or more) of the viaduct or bridge and its approaches, and have plans and specifications prepared therefor. All bids for the work shall be according to and in conformity with the plans and specifications.
N.J.S. § 27:19-14