Every driver has a "favourite" pothole - it's the one you hit on the way home, and then do the same the next night - but by the end of the week you know how to avoid it. Then it gets filled in - but it's back again a few weeks later. (Repeat the process into eternity).
Subscribe now for unlimited access.
$0/
(min cost $0)
or signup to continue reading
Potholes are a jolt to a vehicle's suspension and to the driver. They are a curse, not least to the ACT government which pays out compensation when cars are damaged - $43,000 so far this year, and counting.
Are the Romans to blame?
No - but some people think so.
According to the pothole info website (there really is one): "Folklore has it that the famous road builders of the Roman Empire, more than 3000 years ago, were hampered by potters who dug up chunks of clay from the smooth highways of that time. The clay became pots, and hence the name.
"But that doesn't entirely make sense, since Roman roads were made of a combination of stones, lime, coarse sand and sometimes metal."
A more likely, but less interesting, explanation for the name is that urban potholes are like ones which occur in the wilderness.
"A pothole is a circular or cylindrical hole in the riverbed which is produced by force of water and abrasion. A pothole is formed when a circular current of water carrying small pebbles and sediment begins to wear away a rock surface," according to the Department of Geology at Michigan Technological University.
So now you know.
What causes them?
Water.
"Moisture is the kryptonite of roads which causes potholes," Michael Caltabiano, the chief executive of the Australia Road Research Board, said.
His "favourite" pothole is on the junction of Denman Drive and Forest Drive.
Potholes form when the asphalt surface of the road breaks up. Roads are made of packed stones covered with asphalt (a kind of tar mixed with ground up stones). It seals the road. If water gets under the seal, the base of the road erodes and then when vehicles go over it, the surface cracks and the hole is exposed, and widens and deepens.
Why are they suddenly appearing now?
Because of the wet after the dry.
In the years when there wasn't much rain, there wasn't a problem but in the last two, wet years, the ACT problem has loomed larger.
The ending of the drought brought more potholes - or at least sightings of potholes. Complaints to the ACT government about them more than doubled in 2021 compared with the drier year before. And 2021 saw three times more complaints than the previous even drier year.
In 2020, there were 1292 complaints made, compared to 91 in 2019.
READ MORE:
So it's just the weather?
It is not.
It is also about neglect during the dry weather. Not spending then was a false economy, according to Mr Caltabiano.
"From my observation, the ACT road network is in a poor condition," he said.
"The professional engineers in the roads department know that. They are very capable and competent people but the evidence is that the road system is deteriorating, and ordinary drivers are seeing that," he said.
He sees it himself when he drives home. His "favourite" pothole is on the junction of Hindmarsh Drive and Yamba Drive.
What should be done?
An audit of the ACT's roads to identify the places needing the most urgent fixes. Once priorities are identified, the engineers and road gangs should get to it. "None of this will be a surprise to the engineers in the department," Michael Caltabiano said.
But repair is not easy. Long-lasting repair is expensive. It involves lane closures and heavy equipment to pack down the under-surface mixtures and then to lay the surface.
There are choices between longer-lasting, but more expensive surfaces, and shorter-term but cheaper fixes.
Asphalt by itself, for example, costs $25 a square metre while pure bitumen with a stone coating on top costs $2.50 a square metre (this tends to get used on less busy roads and sounds different when driven on).
Asphalt is more durable and it tends to get used where there are heavy vehicles and buses turning. Bitumen with small stones on top gets used on suburban streets where road use is lighter.
Some definitions
Bitumen is that gooey black stuff, made from oil. It is then mixed with tiny bits of crushed rock and sand to give different textures (that's why it sounds different in different places when you drive on it).
When bitumen is mixed with the crushed rock, it becomes asphalt which is the stuff which actually goes on top of the road.
"Bitumen is known for being strongly adhesive and resistant to damage from water and oil spills. This makes bitumen the ideal binder for asphalt because asphalt is commonly used as a surface for roads, car parks and driveways," according to NK Asphalt, the Australian company which lays car-parks for government and other public buildings.
Get your spelling right
NK Asphalt points out that bitumen is often misspelt: "Common bitumen misspellings: bitumin, bit umin, bitch umen, bitchumen, bitch umen, bitchamen, bitch amen, bichement, biche ment, bichman, bich man, bitchamin, bitch amin, bitchemen, bitche men, bitchimen, bitchi men, bitchimin, bitchman, bitchimum, bitchi mum, bitchmen, bitchomen, bitcho men, bitchumin, bitcumen, bitcu men, or bituman."
We've made it a whole lot easier for you to have your say. Our new comment platform requires only one log-in to access articles and to join the discussion on The Canberra Times website. Find out how to register so you can enjoy civil, friendly and engaging discussions. See our moderation policy here.
Steve Evans
Steve Evans is a reporter on The Canberra Times. He's been a BBC correspondent in New York, London, Berlin and Seoul and the sole reporter/photographer/paper deliverer on The Glen Innes Examiner in country New South Wales. "All the jobs have been fascinating - and so it continues."
Steve Evans is a reporter on The Canberra Times. He's been a BBC correspondent in New York, London, Berlin and Seoul and the sole reporter/photographer/paper deliverer on The Glen Innes Examiner in country New South Wales. "All the jobs have been fascinating - and so it continues."
