Should vehicle rego be paid via the petrol pump?

There's a number of likely explanations for the large number of unregistered vehicles. Some motorists, like Victoria's former Police Commissioner, simply overlook renewing their rego; they're not deliberately avoiding their legal obligation.

It's likely though that there's another group of drivers for whom (a) the chances of detection and the likely penalty are sufficiently low relative to (b) the magnitude of the benefits of driving, that it's a risk well worth taking.

That could be compounded by factors like the high and lumpy cost of registration for those on low to average incomes; the financial and time cost of associated compulsory roadworthiness checks (e.g. in NSW); and the perception that alternative ways of travelling are too expensive (e.g. taxi) or simply aren't good enough (e.g. public transport).

Compliance by "forgetful drivers" might be improved if responsible agencies gave drivers stronger signals that their registration is due or made better payment options available e.g. automatic deductions, discounts for early payment; monthly or quarterly payment option. NSW might review its burdensome annual inspection process to see if the benefits really are worth the costs.

Stronger enforcement seems the obvious way to tackle recalcitrant drivers (i.e. increasing the odds of getting caught), but it's expensive and the law of diminishing returns applies. An alternative option could be a national initiative that abolishes fixed fees in favour of collecting registration/insurance revenue via a surcharge on the price of petrol.

This approach would have a number of advantages. It would be virtually impossible to avoid; it does away with lumpy annual or periodic payments; and it would provide a much more accurate connection between road use and charges than the simple weight/engine size formulae used by the States and Territories at present.

It's arguable if addressing the issue of unregistered vehicles provides sufficient warrant by itself for such a radical change, but another compelling reason is that it would act as a de facto carbon tax with the broad suite of benefits that implies.

Vehicles would still need to be registered for identification purposes, but the associated tax and insurance costs would be "invisible" and hence not a deterrent.

I like this approach because it opens the door for other lumpy costs – like comprehensive insurance – to eventually be charged in accordance with the level of road use. It contributes to motorists getting a better appreciation of what each trip really costs them.