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Most local roads are unsealed, and they fail differently

Three in five kilometres of Australian local road are unsealed. Scoring them with methods designed for sealed pavements gets their condition, their costs and their priorities wrong.

The network most reports underplay

ALGA's 2024 National State of the Assets report, drawing on 458 councils, counts 413,000 km of unsealed local road against 265,000 km sealed: 61% of local road length is unsealed. It also finds a larger share of unsealed roads in poor condition, 13% against 9% for sealed roads. Replacing the unsealed roads already in poor condition would cost about $3.9 billion.

For many rural and regional councils the unsealed share is far higher than the national figure, and so is the share of the maintenance crew's year spent on it.

Why sealed-road methods don't fit

A sealed road is usually judged on cracking, rutting, roughness and surface wear: signs that the seal or asphalt is ageing and water is getting in. An unsealed road fails in other ways: loss of gravel, corrugations, potholes, loss of shape and crossfall, scouring and washouts, and dust. Its life is a cycle of grading and periodic resheeting rather than a slow decline toward resurfacing.

So a single condition index borrowed from sealed roads either cannot see what matters on gravel or reports it in a way that ranks unsealed roads against sealed ones on an unequal footing. Scoring each surface type on its own terms is the starting point for a fair works programme.

The “seal it or keep grading it” question

The World Road Association (PIARC) published a technical report on low-cost pavement systems in 2025. Its main lesson for councils: a low construction cost is not necessarily a low lifecycle cost, so options should be compared over their whole life, maintenance included.

PIARC's guide notes that gravel surfacing tends to suit roads where good gravel is within about 10 km haul, gradients are under about 6%, rainfall is under about 2,000 mm a year, and traffic is below about 200 vehicles a day, with regrading and added gravel typically needed every three to five years. Where those conditions are not met, gravel can be washed away or lost as dust, and the road can revert towards an earth road if maintenance lapses.

PIARC lists the circumstances in which upgrading a low-volume road's surface is usually considered:

It also suggests staged construction, sealing in stages as traffic and funds allow, as a way to spread capital cost and learn how a new surface performs before committing to the final stage. Local conditions decide the answer; the method for reaching it is the same everywhere: compare the options' lifecycle costs, not their first costs.

How PaveKeep handles this

PaveKeep scores sealed roads, sprayed-seal roads and gravel roads by different methods, because they fail in different ways. Unsealed roads are scored on their own terms rather than borrowing a sealed-road method.

The limit, which travels with that feature: unsealed roads are handled as one group. PaveKeep cannot yet report gravel, formed and unformed lengths separately, which some state returns ask for.

PaveKeep is built for small and regional councils and is not yet in use at any council.

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