Within 100 days after the recordation of such certificate, if the Commissioner of Highways and the owner of such lands or interest therein taken or damaged by the Commissioner of Highways are unable to agree as to the compensation or damages, if any, caused thereby, or such consent cannot be obtained due to the incapacity of the owner, or because such owner is unknown or cannot with reasonable diligence be found within the Commonwealth, the Commissioner of Highways shall institute condemnation proceedings, as provided in this article, unless said proceedings shall have been instituted prior to the recordation of such certificate. The amount of such compensation and damages, if any, awarded to the owner in such proceedings shall be paid out of the appropriations to the Department. The final order confirming the award of the Commissioner of Highways shall confirm absolute and indefeasible title to the land, or interest therein, in the Commonwealth and shall be recorded in the current deed book. The Commissioner of Highways and the property owner may mutually agree to delay the institution of condemnation proceedings by written agreement between such parties or counsel for such parties.