Further Information on the Salt Used

 

Every effort is made to treat city roads before the temperature falls to freezing point. Salting routes are reviewed and prepared before the winter maintenance period begins in order to ensure that traffic is disrupted as little as possible.

Salting Operations

Salting operations are reviewed before every new winter maintenance period begins.

  • Salting routes are planned to maximise the length of roads treated in the shortest possible time and to minimise the amount of salt spread thus reducing environmental damage.

  • Salt spreading vehicles are equipped with the latest satellite navigation technology to ensure that the planned routes are followed and that the amount of salt released on the roads is carefully controlled.

    • All the information collected during winter maintenance operations is archived and used to help plan services in future years.

  • Much of the maintenance of salting vehicles and planning of winter maintenance services is done in the height of summer to ensure the service is ready to respond as soon as the first frost is forecast.

  • Whenever possible we endeavour to complete salting operations before the morning rush hour to minimise disruption. 

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Materials

Rock salt is still the most commonly used substance spread on roads because, when it becomes wet, it melts snow and ice.

  • rock salt is a quarried material containing more than 94% pure salt (sodium chlorate)

 

Salt on Ice

Road surfaces can be treated with salt to stop the formation of ice down to minus nine degrees centigrade and, to a lesser extent, at even lower temperatures.

  • Spreading salt to prevent the formation of ice is much more effective than trying to melt ice once it has formed.
  • If ice is already present, heavy traffic can grind the salt into the ice thus helping the chemical reaction along.

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Salt on snow

Snow cannot be treated until it has landed on the roads. We try to get a layer of salt onto the road surface before the snow starts, but if the snow accumulates before traffic passes over it, the effectiveness of the salt is reduced.

 

Alternatives to salt

Urea, glycol, calcium magnesium acetate and anti-freeze are all alternatives to salt however, such alternatives are much more expensive than salt and are only used in rare circumstances

  • urea can be 10 times more expensive than salt

  • Glycol is as much as 20 times more expensive

Glycol is sometimes used on bridges, it does not corrode metal in the same way salt does when it dissolves and soaks into the bridge structure. 

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Sections
An Introduction to Winter Maintenance
Salt Supplies
Common Questions 
Driving Tips
Contacts and Links