If at any time the driveway provisions in this chapter are found to be impracticable in certain cases, the City Engineer is hereby authorized to use his discretion in modifying the strict application of such provisions in order to obtain results that are reasonable, safe and convenient for both the public and the owner.
   In cases where the owner is dissatisfied with the modifications made by the City Engineer, he may appeal to the Mayor, whose decision shall be final.
(1956 Code Sec. 307.06)