Are there maximum driveway widths for a dual occupancy?

Yes. For a driveway serving a dual occupancy, the driveway width is determined by the designer based on the development, but it must not exceed 5.5 m at the property boundary or kerb.

Unlike driveways serving a single dwelling, the standard does not specify a fixed minimum driveway width for two or three dwellings. The appropriate width is instead assessed by the designer. Where additional width is needed—for example, to allow two vehicles to safely pass in opposite directions—the driveway may be designed wider, but cannot exceed the 5.5 m maximum. The width at the property boundary also cannot be greater than the width at the kerb.

Reference: Applicable ACT driveway requirements – Municipal Infrastructure Standard 07 (MIS 07) Driveways, Edition 1 Revision 2 – Section 2.3.2 - Municipal Infrastructure Standard 07 Driveways (Edition 1 Revision 2)