The Commissioner of Transportation is authorized, when in his opinion it would be in the best interest of the state, to enter into an agreement with the owner or operator of a public service facility, as defined in § 13a-126, for the revision, by the owner or operator, of the plans for any proposed public service facility installation when such installation is to be constructed prior to planned highway construction and readjustment or relocation of such installation would be required by the planned highway construction. The added cost of rights-of-way and construction of the public service facility resulting from such revision in plans shall, if the proposed public service facility would have been located within an existing state highway, be paid in accordance with said § 13a-126, or if the proposed public service facility would not have been located within an existing state highway, be paid from appropriations made to the commissioner.