Road gritting and snow clearance

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Helping you drive safely in bad weather

• Adverse Weather 2011/2012 - containing gritting route map 915kb  (This is a printable document for your information)
• Online gritting routes map
• Find out information about current road conditions
• Self help for drivers

When we salt roads

Decisions are based on road temperatures, rather than air temperatures, and salting is likely whenever road temperatures are near freezing. Other factors like moisture, heat retention and time of day or night will influence the decision. Treatment by salt is normally carried out after the evening peak traffic period or before the morning rush. This is because frost and ice do not normally affect road surfaces until late evening or early morning. Usually it takes two hours to complete a salting route.

Which roads we salt

With such a large road network, it would be unrealistic and uneconomic to attempt to treat all roads. All key routes in Wiltshire will receive precautionary salting when ice is forecast. This will include all motorways, trunk roads, class A and B roads and the more important lower class roads. This should ensure the majority of road users live within a reasonable distance of a salted road. This network is under constant review and may be expanded during the current season. Please remember that the majority of minor roads will receive no treatment, and because arrangements may not always go according to plan, you should never assume a road has been salted

If temperatures are predicted to remain below freezing after the morning rush, then a larger network may be salted. This additional network includes mainly lower class roads serving housing estates and main accesses to villages and hamlets.

Should conditions persist, as much of the entire road network as possible will be salted.

Grit bins policy

There are several hundred grit bins on the highway network These are repaired and replenished throughout the winter period as necessary.

Any requests for additional grit bins will only be considered if they are received from City, Town or Parish Councils. Requests direct from members of the public will not be considered.

The positioning of a proposed grit bin will be agreed by the Divisional Highway Manager who will consider the following conditions:

• Bins should not be placed as a permanent measure on the primary salting route unless it is intended for use on a hazardous adjoining road which is not on a salting route.
• Bins should only be placed in areas that are populated and have either a steep incline or a known seepage point.
• They will only be placed where there is a wide verge or footpath and where there is sufficient space for safe salt replenishment.
• Bins will not be placed on roads that are not adopted.
• The bin shall not obstruct sight lines.
• There must be sufficient traffic and/or pedestrian use to justify provision

Should a site prove problematic because of regular misuse of salt for the treatment of private driveways, or vandalism of a bin, Wiltshire Council reserve the right to remove the bin.

The City, Parish or Town Council should advise the Area Highway when the bins in their area are in need of refilling or maintenance. Wiltshire Council will endeavor to keep the bins refilled, subject to other priorities on the highway network.

Information about the location of salt bins can be obtained from the Parish Council for the area.

Why we salt roads

Our aim is to make the county’s roads as safe as possible for road users and to reduce delays caused by bad weather. We salt key routes when there is a risk of ice. The key routes in Wiltshire total a length of 1160km (725miles) which is 25% of the entire maintained road network. Using our fleet of specialist vehicles, we provide a 24 hour response in bad weather. A single precautionary salting treatment will cost, on average, £17,000

Snow clearance

• View the Snow Clearance Priority Routes 5mb

In periods of prolonged snow the main snow clearing resources will be concentrated on priority routes until they have been opened sufficiently to maintain a reasonable traffic flow in both directions. Other roads are then treated in accordance with local priorities and conditions.

Ploughing will commence as soon as there is sufficient depth to plough and it is apparent that snowfall is continuing.

If heavy or continuous falls are predicted a snow emergency will be called and the Emergency Control Centre established. In this event, the county's entire fleet of gritters will be mobilised and supplemented with the council's owned snow blades and blowers that are allocated to local farmers or contractors.

Footways (to include footways, pavements, cycle routes and cycleways) will only be treated in times of persistent ice or snow. When this occurs, salting and snow clearing will be confined to those footways where there is a high pedestrian usage.

The time taken to clear footways will depend on the quantity of snow, the prevailing conditions and the available resources.

Closure of roads and police control

Signs

Wherever possible blocked roads and diversions should be properly signed. The Police will assist in controlling traffic particularly on newly opened sections of road. However, roads will not be opened to traffic until two lanes are clear.

Barriers

It is increasingly evident that snow-clearing plant can only work efficiently when other vehicles are excluded from the site of operations. On two sections of the A303 and one section of A350 gates are provided to close the road.

The expected diversionary routes are:

A303 closure between Amesbury and Mere. - A338 or A345 to Salisbury, A30 to Shaftesbury, B3095 to Mere and A303 and vice versa.

A350 closure between Longbridge Deverill and A303 - A36 Warminster to Wylye, A303 to Furze Hedge and vice versa.

Safecote pilot scheme

In addition to the council’s normal gritting activities, this year we are carrying out a pilot scheme in parts of the county using a salt treatment called ‘Safecote’. This is a derivative of the sugar production process - liquid molasses – and a 3% blend of it is added to rock salt. This process ensures that it spreads better than pure rock salt, and is more effective in dealing with ice, whilst also reducing the amount of saline deposited in our surface water drainage systems. Safecote treated salt has been used in the UK since 2002 by many local authorities, and Wiltshire Council are pleased to be able to trial this product for the first time.

This treated salt has improved capacity so that it adheres to the road surface better than untreated salt, and this reduces the volume of salt required to treat a road. A further benefit is that the Council should be able to reduce the number of times we salt, whilst still keeping the roads free of ice and helping us to deliver a cost effective and environmentally improved winter maintenance service. There is also less dust during times of spreading and gritter maintenance is reduced at the end of a salt run.

Studies have been carried out by various organisations in respect of skid resistance when applying Safecote treated salt to highway surfaces and the conclusions of each study found there to be no reduction in skid resistance when compared to any other de-icing material currently used in the UK.

Whilst there may be some concerns as to what impact this liquid molasses coated product may have on animals that may digest it, to date there is no evidence of increased road kill on any road treated with the product, nor has there been any evidence of this when the material has been used in Europe and North America. The Deer Preservation Society have carried out research on this, and as with the users of the product found no evidence to support an increase in animal road kill.

Studies have also taken place to assess the likely environmental impact on UK streams and rivers of runoff from roads treated with Safecote. Overall there appears to be little risk to the aquatic environment from the use of Safecote, although routine Environment Agency monitoring of streams will provide additional reassurance.

The use of this material will be monitored closely so that the potential benefits can be carefully assessed as part of the pilot scheme, and its further use will be considered once our trials are complete.

Related documents

This is a printable document for your information.

• Adverse Weather 2011/2012 - containing gritting route map 915kb

Maps:

• County wide precautionary gritting route 2011/12 7mb
• North Wiltshire precautionary gritting route 2011/12 3mb
• Central Wiltshire precautionary gritting route 2011/12 (replaces West and East) 3mb
• South Wiltshire precautionary gritting route 2011/12 4mb

Related links

• Met Office : West Country Weather

Last updated: 15 December 2011