No person shall be required to move from his or her dwelling as a result of any publicly financed project unless the head of the displacing agency is satisfied that comparable replacement housing is available to such person. If a publicly financed project cannot proceed on a timely basis because comparable replacement dwellings are not available and the head of the displacing agency determines that such dwellings cannot otherwise be made available, the head of the displacing agency may take such action as is necessary or appropriate to provide such dwellings by the use of funds authorized for such project. The head of the displacing agency may exceed the maximum amounts which may be paid under sections 76-1231 to 76-1233 on a case-by-case basis for good cause as determined in accordance with rules and regulations adopted and promulgated by the head of the lead agency which are consistent with regulations adopted and promulgated by the United States Department of Transportation under the Uniform Relocation Assistance and Real Property Acquisition Policies Act of 1970, Public Law 91-646, as amended.