Every member of any highway contractors’ association who bids upon any work let by the Board or the Commissioner of Highways shall file with his bid an affidavit in substance as follows: that the bidder neither directly nor indirectly has entered into any combination or arrangement with any person, firm, or corporation or entered into any agreement the effect of which is to prevent competition or increase the cost of construction or maintenance of highways or bridges. The Board or the Commissioner or Highways shall prescribe the form of this affidavit and no bid shall be accepted unless accompanied by such affidavit.