23 CFR § 630.110 - Modification of original agreement.
(a) When changes are needed to the original project agreement, a modification of agreement shall be prepared. Agreements should not be modified to replace one Federal fund category with another unless specifically authorized by statute.
(1) The Federal-aid project number and State;
(2) A sequential number identifying the modification;
(3) A reference to the date of the original project agreement to be modified;
(4) The original total project cost and the original amount of Federal funds under agreement;
(5) The revised total project cost and the revised amount of Federal funds under agreement;
(6) The reason for the modifications; and,
(7) Signatures of officials from both the State and the FHWA and date executed.
(c) The STD may use an electronic version of the modification of project agreement as provided by the FHWA.