After the rather confusing (and confused, it turned out) convoy to Canberra and a barrage of intelligence-insulting UAP ads early in 2022 (which also blamed the federal government for state/territory health regulations, so I'm not convinced it was a coincidence of timing) it occurred to me that there are still plenty of people (hopefully a minority, but that's still proven to be thousands) who have no idea which level of government is typically responsible for what.
So, within our topic of motoring, let's partially sort this out with regards to things we're interested in like rules, roads, law enforcement, emergency services and revenue.
The basic tenet is that the federal government looks after national issues, then the states and territories deliver another subset of services and regulations, and then the states can (and do) delegate localised issues to councils.
Each level also collects funding in different (but sometimes overlapping) ways. For instance, the federal government is who collects the GST, but there's a federal and a state/territory excise on vehicle fuels.
The federal government also collects import duty (or tariff) on specific types of goods, partly based on its trade deals and to protect locally made goods. In fact, the greatly reduced tariff on imported cars was at least partly blamed for Ford, then Holden and Toyota, deciding to pack up and close their Australian manufacturing plants.
Some of the things the federal government does involves national strategy and planning. This includes everything from trade deals and aiming to keep the maritime trade routes that matter to us secure (partly by keeping up alliances with other naval powers to maintain access and avoid blockades), and fuel security.
For (part of) Australia's fuel security they subsidise the last two remaining oil refineries in Australia (Ampol's Lytton refinery and Viva's Geelong refinery). Although, if imports stopped, these would be at maximum capacity supplying just a quarter of domestic demand (and we currently import about 90 per cent of what we burn).
Immigration is a federal responsibility. Health restrictions and guidelines once they get here however (and for those already here), are a state and territory responsibility which is why crossing state borders became a drama in 2020. And why the convoy to Canberra protesting state and territory health regulations made no sense at all (so the convoy's misguided anger was also misdirected).
The federal government is responsible for Australian Design Rules (ADRs), so that's all the safety minimums and emissions standards that new vehicles (and new parts, and new accessories) need to comply with.
Road rules and vehicle registrations are state and territory matters though.
Parking inspectors usually work for the council or territory, otherwise it's enforced by the state/territory police.
For a lot of things related to motoring (and many other sectors) what the federal government does is allocate funding.
For roads, the federal government came up with its first national road numbering system in the 1950s to connect the states and territories, and later committed to funding those links. As an example, the flood-worsening levee that is the M1 in the Northern Rivers of NSW is part of that, but the state managed it and the process involved applying to the federal government for funding.
Local roads too can be funded by local council rates, state funds, federal funding, or a combination.
It depends on which road it is as to who manages that project as well, and in many cases for regional roads that will actually be the local council.
Same goes for speed limits. Whomever is responsible for the road decides this too.
There are other things related to motoring that we need to at least remain on standby for us in case of an emergency, or to enforce the laws to reduce the likelihood of one. These fall to the states and territories though. So that's the highway patrol, the ambulances and other rescue services, and the hospitals. Again, the federal level can help by providing funding, but they don't actually deliver these services.