Yes you are correct. Diesels esp those with Diesel Particulate Filters prefer long freeway/highway drives to get it up to temperature to carry out a Passive regeneration. If you only travel in the suburbs, when the DPF fills up, the car will carry out an Active regen.
A 30min drive at 100km/h once a fortnight should keep your DPF happy.
Using a fuel additive with Cerium may help
Penrite Oil | ENVIRO+ DPF CLEANER
DIESEL PARTICULATE FILTER (DPF) ANTI-CLOG | 2729 – LIQUI-MOLY Australia
Some light reading on DPF regens
Passive regeneration
How Diesel Particulate Filters Work
Bookmarks