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Cold leaves roads full of holes Cold leaves roads full of holes
(40 minutes later)
Councils across Scotland are counting the cost of the damage to roads caused by three weeks of freezing weather.Councils across Scotland are counting the cost of the damage to roads caused by three weeks of freezing weather.
The cold snap has left many areas with a hefty programme of repairs and roadworks.The cold snap has left many areas with a hefty programme of repairs and roadworks.
Some local authorities have spent far more on winter maintenance than they had anticipated.Some local authorities have spent far more on winter maintenance than they had anticipated.
Routine work has fallen behind because teams were busy trying to keep the roads open, or the cold weather made scheduled work impossible.Routine work has fallen behind because teams were busy trying to keep the roads open, or the cold weather made scheduled work impossible.
The freeze has damaged the roads and one of the biggest problems is potholes.The freeze has damaged the roads and one of the biggest problems is potholes.
Motoring organisations believe there are likely to be substantially more holes than normal this year.Motoring organisations believe there are likely to be substantially more holes than normal this year.
Neil Greig, of the Institute of Advanced Motorists, said: "There's no doubt this is one of the worst periods for potholes and road surface deterioration which we've seen for some time."Neil Greig, of the Institute of Advanced Motorists, said: "There's no doubt this is one of the worst periods for potholes and road surface deterioration which we've seen for some time."
Potholes start to form because road surfaces eventually crack under the heat of the day and the constant stresses of traffic.Potholes start to form because road surfaces eventually crack under the heat of the day and the constant stresses of traffic.
SEND YOUR POTHOLE PICS Email: newsonlinescotland@bbc.co.uk, subject POTHOLEMMS from UK: 61124Don't forget to include your name and where your picture was taken Terms and conditionsSEND YOUR POTHOLE PICS Email: newsonlinescotland@bbc.co.uk, subject POTHOLEMMS from UK: 61124Don't forget to include your name and where your picture was taken Terms and conditions
Snow and rainwater seep into cracks, and during cold snaps the water freezes.Snow and rainwater seep into cracks, and during cold snaps the water freezes.
Some of the dirt and gravel is pushed out as a result, leaving a hidden hole underneath the surface once the water melts.Some of the dirt and gravel is pushed out as a result, leaving a hidden hole underneath the surface once the water melts.
Eventually the road surface above collapses - creating potholes.Eventually the road surface above collapses - creating potholes.
Aberdeenshire Council last week appealed for residents to alert them to pothole problems.Aberdeenshire Council last week appealed for residents to alert them to pothole problems.
Angus Council has warned motorists and pedestrians it was going to take "some time" to carry out repairs following the big freeze.
Argyll and Bute Council is responsible for maintaining some 2,300km of roads on the mainland from Helensburgh to Campbeltown and Oban, as well as several islands including Mull and Islay.Argyll and Bute Council is responsible for maintaining some 2,300km of roads on the mainland from Helensburgh to Campbeltown and Oban, as well as several islands including Mull and Islay.
Stewart Turner, the head of roads at the council, said that this winter was the worst he had experienced in 25 years in the industry.Stewart Turner, the head of roads at the council, said that this winter was the worst he had experienced in 25 years in the industry.
He added: "The thing that we've noticed this year is the amount of frost heave that we've got. That's when pavements rise up and roads themselves rise up because there's so much water in the ground - it's a bit like frozen pipes."He added: "The thing that we've noticed this year is the amount of frost heave that we've got. That's when pavements rise up and roads themselves rise up because there's so much water in the ground - it's a bit like frozen pipes."
Conditions like this, he said, add to the likelihood of potholes.Conditions like this, he said, add to the likelihood of potholes.

How potholes are formed

As tarmac ages, it gets more porous. Rainwater penetrates cracks caused by constant traffic use.
When water freezes it expands. More cracks form and the tarmac is pushed outwards like a bubble.
The ice thaws creating voids, or gaps, under the surface. These get larger with each freeze-thaw cycle.
Traffic causes tarmac to collapse and form a pothole which gets larger as more traffic rolls over it.
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How potholes are formed

As tarmac ages, it gets more porous. Rainwater penetrates cracks caused by constant traffic use.
When water freezes it expands. More cracks form and the tarmac is pushed outwards like a bubble.
The ice thaws creating voids, or gaps, under the surface. These get larger with each freeze-thaw cycle.
Traffic causes tarmac to collapse and form a pothole which gets larger as more traffic rolls over it.
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Mr Turner said that the condition of roads across Argyll and Bute is now being checked and potholes are being noted.Mr Turner said that the condition of roads across Argyll and Bute is now being checked and potholes are being noted.
The authority will then have to prioritise how to deal with them.The authority will then have to prioritise how to deal with them.
The most important roads and the most potentially dangerous potholes would come first.The most important roads and the most potentially dangerous potholes would come first.
Mr Turner's experiences are likely to be replicated across Scotland.Mr Turner's experiences are likely to be replicated across Scotland.
There are two main ways of repairing potholes and experts liken them to the temporary and permanent fillings used by dentists.There are two main ways of repairing potholes and experts liken them to the temporary and permanent fillings used by dentists.
During the winter months, potholes may receive what is known as a "cold winter mix".During the winter months, potholes may receive what is known as a "cold winter mix".
It is a temporary solution to fill in the hole and make the road surface smoother, but holes repaired in this way are likely to appear again after a few weeksIt is a temporary solution to fill in the hole and make the road surface smoother, but holes repaired in this way are likely to appear again after a few weeks
A more permanent fix for potholes is called a "hot summer mix".A more permanent fix for potholes is called a "hot summer mix".
This combination of roadgrade asphalt and aggregate is designed to last for years, but it can only be applied during dry, warm weather.This combination of roadgrade asphalt and aggregate is designed to last for years, but it can only be applied during dry, warm weather.
Pat Watters, president of local government umbrella body Cosla, said: "Central and local government are working to address long-standing underinvestment in our road network and there is no doubt that roads have been affected badly by the freeze.Pat Watters, president of local government umbrella body Cosla, said: "Central and local government are working to address long-standing underinvestment in our road network and there is no doubt that roads have been affected badly by the freeze.
"However the cost of repair is not really our focus at the moment."However the cost of repair is not really our focus at the moment.
"Delivering services and keeping Scotland safe and moving are our first priorities.""Delivering services and keeping Scotland safe and moving are our first priorities."