Dorset Highways Winter Service Policy

1. Winter Service – Statutory Duty

Dorset Council, in its capacity as the local highway authority for Dorset, has a statutory responsibility in respect of Winter Service which is set out Section 41 Highways Act 1980 - Duty to maintain highways maintainable at public expense.

In particular, Section 41(1)(A) details that a highway authority is under a duty to ensure, so far as is reasonably practicable, that safe passage along a highway is not endangered by snow or ice.

The council’s Winter Service is essential in aiding the safe movement of highway users, maintaining communications, reducing delays, and enabling everyday life to continue. The council must prioritise its response to winter weather whilst exercising due regard to logistics and available resources.

2. Winter Service – Standards

Dorset Council’s Winter Service policy follows the recommendations issued by the UK Roads Liaison Group in its document “Well-Managed Highway Infrastructure” and the National Winter Service Research Group’s “Practical Guide for Winter Service”.

These documents are reviewed annually, and any recommendations are included within our policy where practical.

Consistency with the policies of neighbouring authorities is considered and applied when reasonably practicable.

Dorset Council provides a Winter Service which, as far as is reasonably practicable, will:

  • minimise the risk of loss of life and injury to highway users, including pedestrians; and prevent damage to vehicles and other property
  • keep the highway free from obstruction, thereby avoiding unnecessary delay to passage

Part 1 of this document sets out the policies and standards for each of the winter service activities which enable the council to respond as quickly and efficiently as possible in meeting its Winter Service responsibilities.

The operational details for the council’s Winter Service activities are set out in the Winter Service Operational Plan.

The Council’s Winter Service forms part of Dorset Highways Adverse Weather Plan (See Appendix 1 of the Winter Service Operational Plan), which sets out Dorset Council’s arrangements for managing the impact of adverse weather on the highway network.

3. Winter Service Season

The Winter Service season will run for a prescribed period from 1 October to 30 April.

4. Winter Service – Scope of Application

Dorset Council’s Winter Service applies to roads that are classified as highway maintainable at public expense, within the administrative area of Dorset Council.

The Department for Transport (DfT) is the highway authority for trunk roads, and National Highways are the government company charged with operating, maintaining, and improving trunk roads on behalf of the DfT. This responsibility includes Winter Service and as such, Dorset Council has no statutory responsibility for winter service activities on these roads.

Dorset Highways and National Highways liaise closely during the winter service operational period.

5. Winter Service Objectives

The objectives that we achieve are:

  • Precautionary Salting: To prevent the formation of ice on carriageways
  • Post Salting: To facilitate the removal of ice and snow from carriageways
  • Snow Clearance:
    • to prevent injury or damage caused by snow
    • to remove obstructions caused by the accumulation of snow (section 150 Highways Act 1980)
    • to reduce delays and inconvenience caused by snow

6. Winter Service Networks

6.1 Precautionary Salting Network:

The precautionary salting network comprises those lengths of highway that qualify for treatment whenever ice, frost or snowfall is forecast.

Roads to be included within the precautionary salting network include:

  • all roads defined as having the following Network Classes:
    • Network Class 2 – Strategic Roads
    • Network Class 3 – Main Distributor Roads
    • Network Class 4 – Secondary Distributor Roads
    • all A, B and well-used C class roads
  • links to hospitals, large industrial estates, transport interchanges, emergency service stations and identified critical infrastructure (including manned Coastguard and RNLI)
  • routes to all urban schools with more than 500 pupils
  • routes to all rural schools with more than 350 pupils
  • primary bus routes with a substantial frequency (not including school bus routes)
  • main routes through towns and villages with populations of more than 750 that do not meet any of the criteria set out above

Each precautionary route will have an assigned Winter Service vehicle which is capable of having a snow plough fitted when required.

Consideration will be given to salting diversion routes where interruptions to the precautionary network have occurred.

The aim of this criteria is to treat those roads used by the majority of the travelling public.  The precautionary salting network extends to 1,100km – which is approximately 28% of Dorset’s overall road network.

A plan of the Precautionary Salting Network is contained in Appendix 2 of the Winter Service Operational Plan.

6.2 Community Links Network:

The Community Links Network is a secondary network that serves the smaller villages and hamlets as defined by the Network Operations Service Manager. These routes will be treated where temperatures remain at or below freezing for prolonged periods, and pre-treated following a snow forecast. 

Following snowfall the Community Links Network will be ploughed and salted as resources allow.

A plan of the Community Links Network is contained in Appendix 3 of the Winter Service Operational Plan.

6.3 Footways:

The Council’s policy is not to treat any of the footway network unless in extreme conditions and then only when resources are available.

It would be impractical and financially draining to carry out precautionary salting of footways, pedestrian precincts, or cycleways and therefore no provision has been made. However, there will be a certain amount of salt overspill onto footways and cycleways when precautionary salting is being carried out on adjacent carriageways.

Post salting of footways and cycleways will be carried out on a priority basis during severe weather as resources permit.

6.4 Priority Ploughing Network:

During heavy and prolonged snowfall, the Priority Snow Ploughing Network will be cleared and treated.

A plan of the Priority Ploughing Network is contained in Appendix 4 of the Winter Service Operational Plan.

Snow clearance of some additional minor routes may be carried out by local farmers and contractors under agreement with the Council.

Snow clearance on other minor routes will be carried out as resources permit and some routes and cul-de-sacs will be left to thaw naturally.

Snow clearance on footways and cycleways will only be carried out by Dorset Highways if resources are available. Some towns and parishes will carry out clearing of priority footways when and as their resources become available.

7. Winter Service Updates

The council’s online Winter Service pages includes updates on roads which are currently being treated, those which will be treated soon and those treated within the last 7 days.

All Dorset Council Winter Service information can be accessed here, and you can find out about salting updates here.

8. Winter Service Preparation

Before 1 November each year the following operations shall be completed:

  • ensuring salt stocks have been replenished
  • all salt bins filled
  • bulk salt supplies and dumpy bags delivered to town and parish councils
  • Service Level Agreements are in place with snow ploughing contractors
  • training days are arranged and delivered for all staff involved in implementing the winter service
  • all gritters are serviced and calibrated
  • all operatives are trained, competent and are working towards or have achieved appropriate accreditation
  • moisture content of salt is tested and recorded
  • liaise with neighbouring authorities to identify best practise

9. Weather Information Systems

An effective and efficient Winter Service is only possible with reliable and accurate information about weather conditions. Without this information it is not possible to make effective and appropriate decisions on the winter service operations.

Dorset Highways utilises weather forecast information provided by DTN to ensure that decisions are based on the most accurate data available.

10. Weather Reports

During the Winter Service period Dorset Highways receives detailed weather forecasts and reports specifically dedicated to the highway network and based upon 4 weather domains, and the 22 salting routes within Dorset. This data is based upon both national weather forecasts and data collected from 11 roadside weather stations positioned across the county.

11. Winter Service Duty Engineers

Experienced members of staff from Dorset Highways will act as Duty Engineers throughout the Winter Service Period on a 7-day rota basis.

The Duty Engineer is responsible for:

  • receiving forecast information from the forecast provider
  • monitoring current weather conditions
  • issuing salting instructions for the precautionary network based on the and the 22 precautionary salting routes
  • posting the forecast decision on the Icelert Bureau and on the DTN system
  • assisting and advising during snow events and severe weather events
  • convening the “Incident Management Team” as required in an extreme weather event scenario (See section 13.3)
  • establishing liaison/contact with Dorset Police Control Room
  • participating in any teleconferences convened

12. Salting

12.1 Precautionary Salting:

Precautionary salting will take place on the Precautionary Salting Network on a pre-planned basis to help prevent the formation of ice, frost and/or the accumulation of snow on carriageway surfaces.

12.2 Post Salting:

Post salting will normally take place on the Precautionary Salting Network to treat ice, frost and snow that has already formed on carriageways.

Post salting may, in exceptional circumstances, also be carried out on roads or sections of roads beyond the scheduled precautionary salting routes.

12.3 Spot / Ad-Hoc Salting:

Spot salting may take place on parts or sections of the scheduled salting routes either to help prevent formation of ice, frost and / or accumulations of snow or as a treatment to ice, frost and the accumulation of snow that has already formed on the carriageway.

The Highway Duty Engineer will evaluate and consider if spot treatment is suitable and reasonably practicable, using the following criteria below:

  • has the request come from the emergency services?
  • is there an ongoing emergency at the location?
  • do we have multiple reports of hazardous conditions at the location?
  • what are the prevailing and forecast weather conditions at this location based on the latest forecast from the weather forecast provider?

Spot salting will only take place beyond the scheduled salting routes in exceptional circumstances.

Depending on the situation and widespread weather conditions we may choose to deploy signs or close the road rather than salting the area.

The Duty Engineer will evaluate and consider what treatment is suitable and reasonably practicable, using the following criteria below:

  • has the request come from the emergency services and is it relating to an ongoing emergency at the location?
  • has there been a report of an accident at the location and does the risk exists for further serious accidents?
  • any action taken must not affect the treatment of the scheduled salting routes
  • what are the prevailing and forecast weather conditions at this location based on the latest forecast from the weather forecast provider?

12.4 Instructions to Salt the Precautionary Salting Network:

Instructions for precautionary salting of the network will be issued if road surface temperatures are expected to fall below 1ºC unless:

  • road surfaces are expected to be dry, and frost is not expected to form on the road surface
  • residual salt on the road surface is expected to provide adequate protection against ice or frost forming

Instructions for salting of the precautionary network will also be issued if snowfall is expected.

The Duty Engineer will issue the instructions for precautionary salting of the network for each of the 22 precautionary routes. These decisions will be posted on the Icelert Bureau and on the DTN system.

The Duty Engineer may issue instructions for post and spot salting and will log these decisions on the Icelert Bureau and on the DTN system.

12.5 Instructions to Salt the Community Links Network:

The Duty Engineer will issue instructions to pre-salt the Community Links Network if snow is forecast, or if temperatures are expected to fall below freezing for a prolonged period.

These decisions will also be posted on the Icelert Bureau and on the DTN system.

There is an expectation that pre-salt action on the Community Links Network would be completed within 6 hours of the action being called.

12.6 Salt:

6mm dry rock salt is used across the county for precautionary and post event salting.

Where heavy snowfall has occurred grit sand will be added to the salt and/or spread on its own to aid traffic movement.

The moisture content of salt plays a major part in the spread rate decision making process.

For optimum performance rock salt should have moisture content of between 2 – 4%.

Moisture contents more than 1% outside of this range must be reported to the Duty Engineer.

Potential actions when salt is outside optimum moisture content range include:

Wet (> 4.5%):

  • Review spread rates and increase to account for poorer distribution
  • Consider moving wet salt away from the stockpile to dry (in a suitably contained area to minimise environmental impact)
  • When the moisture content reaches the optimum range, the salt can be mixed with drier salt in the stockpile or from new deliveries
  • Samples should be checked after mixing to confirm that the moisture content is in the optimum range

Wet (< 4.5%):

  • Review spread rates and increase to account for poorer distribution
  • Consider mixing with drier salt in the stockpile or from new deliveries
  • Samples should be checked after mixing to confirm that the moisture content is in the optimum range


  • For dry salting, assume high losses after spreading
  • Consider mixing with salt of higher moisture content in the stockpile or from new deliveries

The moisture content of the salt at each of the storage points will be tested as follows:

  • on delivery
  • before calibration of spreaders
  • once per month through the winter season at all covered depots
  • ad-hoc testing following any specific issues relating to spread rates

12.7 Calibration of Spreaders:

All spreaders are to be calibrated as follows:

  • before the start of each Winter Service season
  • mid-season - One vehicle from each depot to be checked and calibrated at 25 run intervals
  • following incidents or conditions that may require recalibration

Should appropriate calibration settings not be met, the Duty Engineer must be contacted so route specific spread rate(s) can be adjusted.

Calibration procedures are to be in accordance with Well Managed Highway Infrastructure and NWSRG guidance.

12.8 Salt Stocks:



Minimum Stock













Gibbs Marsh






Salt stocks will be replenished before 1 November each year.

Minimum stock levels are maintained for the core winter service period.

Dorset Highways will arrange for the Stock Control Spreadsheet, held within the Winter Service and Emergency folder on the highways computer server to be updated following each treatment of the network.

Dependent on usage, salt stock levels will be replenished as required to ensure minimum stocks are held. This will be subject to the control of the Government’s ‘Salt Cell’.

12.9 Route Treatment Times:

For spread rates of 20g per m2 or less, the Precautionary Salting Network will be fully treated within 2.5 hours of instructed commencement time.

12.10 Emergency Treatment Times:

When an urgent instruction to treat the Precautionary Salting Network is issued by the Duty Engineer, the treatment of the network will commence within 1.5 hours.

12.11 Level Crossings:

Salting will not take place across level crossings as this can adversely affect track side communications.

13. Severe Weather Conditions

13.1 Persistent Ice on Minor Roads:

During longer periods of cold weather, the Duty Engineer may instruct salting to deal with persistent ice on minor roads which are not included within the Precautionary Salting Network or Community Links Network, and invoke arrangements with Town and Parish councils to take action in their area.

13.2 Ice and Snow Emergencies:

During the winter months the likelihood of an extreme weather event increases, and it is essential that a clear management process is in place to ensure that the necessary resources are effectively deployed, and all internal and external stakeholders are involved and informed as necessary.

The weather forecast provider (DTN) will inform Dorset Highways well in advance of any severe or extreme weather event, and on receipt of this information a meeting of the “Incident Management Team” will be convened.

The Incident Management Team will consist of:

  • Corporate Director – Economic Growth and Infrastructure (Chair)
  • Head of Highways
  • Network Operations Service Manager
  • Community Highways Manager
  • Senior Site Agents
  • Emergency Planning Representative
  • Traffic Team Leader
  • Duty Engineer
  • Communications Officer
  • Duty Gold Officer
  • Duty Silver Officer
  • Adult Services Representative
  • Children Services Representative
  • Dorset Direct Representative

At this meeting all operational arrangements and procedures will be agreed and implemented (See section 19 of the Winter Service Operational Plan), and necessary press releases issued. Contact details are contained within the LICOS system.

14. Snow Clearance

14.1 Instructions for Snow Clearance:

Snow clearance will initially take place on the Precautionary Salting Network when snowfall is light.

During heavy and prolonged snowfall, instructions may be issued to clear and treat the Priority Snow Ploughing Network as detailed below and in the Winter Service Operational Plan.

Once this network is clear resources will be directed to clear the rest of the precautionary salting network.

14.2 Priority Ploughing Network: 

Roads to be included within the priority ploughing network include:




A31 Monkeys Jump to Somerset Boundary (*)


Shaftesbury to Yeovil, Somerset Boundary


Bere Regis to Holes Bay Roundabout


Portland, Easton Square to A35, Tesco Roundabout


Junction A35 to Blandford


Blandford Bypass


Blandford to Wiltshire Boundary (**)


A35 Bakers Arms to A31 Roundabout


A31 Roundabout to A354 Blandford


Blandford to Shaftesbury to Wiltshire Boundary


A35 to Blackwater Junction


Blackwater Junction to A31 Canford Bottom Roundabout


A31 Tricketts Cross to Bear Cross Roundabout


Dorchester to Wareham to A35 Bakers Arms Roundabout


A352 Warmwell r/bout to Weymouth


Bridport to Somerset Boundary, Misterton


Junction A37 to Somerset Boundary, Misterton


A37 Charminster to A30 Sherborne


A352 Sherborne – A357 Lydlinch


Swanage to Wareham


Blandford to Henstridge


Shaftesbury to Gillingham to A303

* and ** - extra resources may be required to clear these roads.

As and when resources become available instructions will be issued to plough and treat the Community Link Network.

Snow ploughing will not take place on carriageways where there are physical restrictions due to traffic calming measures unless it has been deemed safe to do so following a formal risk assessment and a safe method of operation documented.

14.3 Snow Clearing of Footways:

The clearance of footways will take place as and when resources become available, some of the towns and parishes have arrangements in place to clear shopping areas and other well used public accesses.

14.4 Farmers and Contractors Snow Ploughs:

Some Parish and Town councils have their own arrangements in place to plough and treat the network within their boundaries.

The council has a database of farmers who will assist in clearing certain roads on the remainder of the network that compliments both the precautionary salting and community link networks.

Dorset Council will engage farmers / contractors directly to clear specific routes such as the precautionary salting network, priority ploughing network, community link network and other roads designated by the Duty Engineer as conditions dictate.

15. Roadside Salt Bins

The council does not provide salt bins and it is the Town and Parish council’s choice, should they require a salt bin(s) within their community, to purchase and place the bins following consultation with the council.

Roadside salt bins can be sited at potentially hazardous locations for use by the public to treat ice and snow over small areas of the carriageway.

The council has classified all salt bins on its network as either a ‘strategic’ or ‘community’ bin.

At the start of each winter all salt bins will be filled with salt, the cost of which will be borne by the council.

Following this initial fill, only those bins classified as ‘strategic’ will be refilled during the winter by the council at its own cost. 

In the event of severe weather, further refills will be carried out as time and resources permit. 

Community bins are the responsibility of the Town or Parish councils to refill. If councils require Dorset Council to fill these bins, this will be subject to a charge as agreed by Dorset Council members. 

Town and Parish Councils can purchase 1 tonne dumpy bags of salt from the council and, as with Community bins, a charge will be made for this service. 

No salt bins will be located on the precautionary salting network.

A specific salt bin policy and assessment sheet for the categorising of salt bins is available from the council upon request.

16. Budgets

16.1 Winter Service Budget:

The budget allocated for the delivery of the Winter Service is reviewed annually and is managed by the Service Manager for Network Operations within the Highways Service.

16.2 Severe Ice and Snow Events:

There is no specific budget allocation to respond to severe ice and snow events.

The cost of dealing with the events will be met by virement of budgets from other planned programmes of work , or from special contingency funds for emergencies.

17. Public & Media Communications

17.1 Neighbouring Authorities and other Agencies:

Dorset Highways will notify neighbouring highway authorities and other appropriate agencies of its intended Winter Service action for Dorset on a daily basis during the Winter Service Period so that activities can be co-ordinated regionally.

17.2 The Media:

Communication with communities, businesses and emergency services during the Winter Service Period is essential to delivering an effective service.

Local media organisations will be informed when instructions for salting the precautionary network are issued.

The Dorset Council website will be updated regularly and salting updates can be accessed here.

Dorset Highways also uses social media to communicate decisions and actions taken.

17.3 Pre-Season Publicity:

It is important that the public are aware of, and understand, the Council’s approach to delivering its Winter Service. This will be done via a pre-season press release with all relevant information made available on the council’s website.