Frontage road easements of 50 feet plus a buffer strip of 10 feet and a frontage road with shared entrances shall be provided whenever two or more permitted uses exist on abutting lots or within 1,320 feet of each other when property is zoned A-2, Agribusiness, C-LI, Commercial/Light Industrial, or HI, Heavy Industrial. Frontage road access points shall occur at intervals of not less than 1,320 feet or four per mile. These requirements may be waived at the discretion of the Story County Engineer if predicted traffic volumes associated with existing and proposed land uses do not indicate declines in existing level of service standards.