Idaho Code § 61-511
Whenever the commission, after a hearing had upon its own motion or upon complaint, shall find that application has been made by any corporation or person to a railroad corporation for a connection or spur as provided in sections 61-324 and 61-325, and that the railroad corporation has refused to provide such connection or spur and that the applicant is entitled to have the same provided for him under said sections, the commission shall make an order requiring the providing of such connection or spur and the maintenance and use of the same upon reasonable terms which the commission shall have the power to prescribe. Whenever any such connection or spur has been so provided any corporation or persons shall be entitled to connect with the private track, tracks or railroad thereby connected with the railroad of the railroad corporation and to use the same or to use the spur so provided upon payment to the person or persons incurring the primary expense of such private track, tracks or railroad, or the connection therewith or of such spur, of a reasonable proportion of the cost thereof to be determined by the commission, after notice to the interested parties and a hearing thereon: provided, that such connection and use can be made without unreasonable interference with the rights of the party or parties incurring such primary expense.
Idaho Code § 61-511