Check which roads are gritted in Suffolk

Check which roads are gritted

Suffolk Highways is responsible for the delivery of this service in Suffolk except for trunk roads, which are the responsibility of National Highways. The winter season runs each year from 1 October to 30 April.

To view a map of all Priority 1 and Priority 2 gritting routes across the county, visit one.network.

Select data layers (3 lines on the search box) driver information and winter gritting routes.

• Purple – Priority 1 routes (primary)
• Green – Priority 2 routes (secondary)

What do we treat?

Priority 1 routes (approximately 1259 miles) 36 routes:

• All A and B roads
• Roads to 24 hour fire stations, accident and emergency hospitals, main bus and rail stations - where the road meets the public highway
• All roads where the traffic flow exceeds 4000 vehicles a day
• Locations at high risk from the occurrence of major civil emergencies where practicable.
• Consideration is given to roads with a traffic flow that falls between 4000v/day to 2000v/day where there are additional risk factors including but not exclusively:
  • 5 day a week bus services where practicable.
  • extended gradients in excess of 5% (1:20) where practicable.
  • high peak hour flows
  • automated railway level crossings on passenger lines where visibility is limited.
  • access to main high schools, where practicable.
  • centres of employment where large numbers of employees are bussed in, where practicable.

Priority 2 routes (843 miles) 34 routes:

• Other bus routes where the service level is 5 days a week in the school term, and a public service licensed vehicle is used (where practicable)
• Cohesive network serving all main centres of population in the rural areas.
• All other routes carrying in excess of 2000v/day.
• Routes added at the Asset Manager (Winter and Soft Estate) discretion where the following are additional risk factors (subject to operational and access constraints):

• high peak hour flows
• access to other schools
• gradients in excess of 5%(1:20)

When do we treat?

Priority 1 routes:

• The objective is to complete the treatment of priority 1 routes 1 hour before the onset of the hazardous conditions under 1 Celsius and within 2½ hours of starting the treatment
• Timing is calculated from starting from the depot to completion of salting

Priority 2 routes:

• Treatments on priority 2 routes are carried out when the forecast predicts there to be a longer period of hazardous conditions
• Treatment will normally be carried out in the morning with the view to completion by 7:30am and the commencement of the main commuter traffic flow

Combined, these routes cover approximately 51% of all roads maintained by Suffolk County Council. Find out more in our Winter Service Plan.

We decide to spread salt on the roads by working closely with our weather forecaster who uses information from our own weather monitoring stations which are strategically located across our County.

What does salting do?

Spreading salt on the roads helps to prevent or remove ice. However, it becomes less effective as temperatures reduce.

In exceptionally low temperatures, salt may have little or no effect. In these cases it may be necessary to spread grit to give more grip on the ice, rather than trying to melt it.

When snow is more than 50mm deep, it needs to be mechanically removed by ploughing or digging. There are practical limitations to what can be achieved, and priority is always given to roads carrying the most traffic or important bus routes.

You can also:

• visit the National Highways website for information about travel and possible transport disruption
• go to the Met Office website to see the latest weather report

Grit bins

We stock 2100 grit bins across the county at important locations, such as the bottom of hills, or on junctions on minor roads. Read more about grit bins.

Grit bins are owned by parish/town/district councils and to ensure that the contents of grit bins are used to make roads safer, we ask these organisations to monitor how and where the grit is used. 

Suffolk Highways will only consider requests for new roads to be added to the gritting routes, new grit bin requests or requests to refill the grit bins from the relevant parish, town or district council.

A pre-season refill is delivered on a countywide basis ahead of the core winter season commencing. Further ad-hoc refill requests can be made via our online reporting tool by selecting problem type "Snow, ice and gritting", problem sub type "Grit bins refill". This will enable you to plot the exact location of the grit bin that requires a refill.

Please note that after prolonged periods of low temperatures or snow events we may opt for a localised refill programme to remain efficient on the refilling of grit bins.

Community involvement

You can clear snow and ice from pavements yourself. It's unlikely that you'll be sued or held responsible if someone is injured on a pavement if you’ve cleared it carefully. The government gives advice about clearing snow from a road, path or cycleway.

Snow ploughing is carried out in severe snow conditions. We do this to keep the most important roads passable (this is normally confined to the busier A class roads). There could be considerable delay in clearing snow from some minor roads.

To supplement our own resources, we call on farmers and contractors across the county to help with clearing snow and ice during the winter months on roads where we cannot plough. All our farmers and contractors sign up to a snow clearing contract. Suffolk Highway is always willing to consider applications from farmers and contractors who have suitable machinery available for hire with operators.

If you would like to find out more information on becoming one of our snow clearance contractors please contact customer services on 0345 606 6171 or send us a letter of interest to:

The Winter and Soft Estate Team
Phoenix House
3 Goddard Road
Ipswich
IP1 5NP

We also clear snow from heavily used pavements. Priority is given to:

• main shopping streets in town centres
• other town pavements
• well used cycle tracks

Why are some roads treated and some are not?

Our 36 vehicles grit 52 per cent of the road network. Suffolk is a large geographical area and weather conditions and road surface temperatures can vary across the road network on the same night. Suffolk has therefore been divided into 4 domains (West Suffolk, Central Suffolk, Ipswich and Coastal) and each of these domains has a separate weather forecast based on weather station data (there are 11 weather stations around the county) and treatments are tailored to different weather conditions. Therefore, there may be occasions when we grit some parts of the county but not others.

How do we decide when treatment is needed?

At midday every day during the winter period (1 October to 30 April), our team of decision makers receive a weather forecast. Treatments are planned on a forecast of a road surface temperature trigger of 1 degree C or less - this is different to the air temperature which can be noticeably higher. They use the forecast to decide whether to send out the gritters, in which areas and how much salt needs to be spread. We check the forecast at 5am, midday, 5pm and 11pm to help us make the decision about when to go out or to alter any previous decision as road surface temperatures can dip below 1 degree C overnight. Our gritters will usually go out after evening rush hour when the roads are quieter – but can go out throughout the night depending on the weather. We aim to complete all salting 1 hour prior to the onset of the hazard.

Why are some gritters not spreading salt?

Our gritters are far more sophisticated than they were years ago. Rather than spraying salt in all directions, the computer-controlled mechanics now dispense the required amount of salt directly down on to the road and can do so at a certain angle. The drivers can control the direction of salt and the width of spread to ensure the whole carriageway is covered even if the vehicle is driving down one side only. This also happens on a roundabout.

Gritters won’t start gritting the moment they leave the depot – all our drivers have specific routes and the vehicle may not have reached the starting point of its treatment route or may be returning to the depot at the end of its route or to refill. Gritters may also cross or part drive roads on other routes, when this occurs the gritter will cease treating. Once they return onto their prescribed route they will commence treating again.

Each gritting vehicle has a GPS system which tracks its route, speed, whether it is spreading salt, and if so, the amount being spread. The date and time a vehicle was on a certain road and what it was doing is always recorded. Drivers will alert the Duty Manager at each depot should there be a road closure and the vehicle need to deviate from its usual route.

Does salting on a road prevent the formation of ice?

Spreading salt on the roads lowers the freezing point of water, helping to stop ice from forming. However, in exceptionally low temperatures (below -8C), salt may have little or no effect. Always check the advice of the emergency services before heading out - even when roads have been gritted, road users must still travel with care as the roads may still be slippery.

Does the county have enough salt?

The county has the capacity to hold sufficient stock for an average winter. We will start the winter season at full stock capacity which is approximately 22,700 tonnes of salt, more salt can be ordered in if required.

Our salt is stored undercover in purpose built salt storage facilities within our 8 operational depots that are strategically located across the County.

What type of salt is used?

De-icing salt 6mm sodium chloride (rock salt) in compliance with BS3247:2011

How do you ensure that Suffolk Highways does not run empty on salt?

We have a constant record of how much salt we currently have, and we are in contact with national suppliers to monitor deliveries. Stock levels are recorded on a regular basis throughout the winter season and reported to central government. The stock information provided to central government has been used to ensure that deliveries of salt are distributed to the local authorities who are most in need of supplies to prevent authorities running out of salt at times of shortage.

How is salt effective?

Water freezes when it reaches 0C. Salt mixed with water or moisture lowers this freezing point. The colder the temperature and the more water present, the more salt is required to lower the freezing point. The effectiveness of salt begins to lessen at about -3/4C, and by -6C the quantity of salt required to remove snow or ice becomes ineffective. A small handful of salt (approximately 20g) can treat approximately 1m/3ft squared of cleared surface. If snow and ice have already formed on the roads and pavements, then adding salt will not help because there is no direct moisture for the salt to dissolve into. Snow and ice must be manually removed first.

What has been the salt usage for the last few years?

• 2013-14 – 9,471 tonnes
• 2014-15 – 15,685 tonnes
• 2015-16 – 8,465 tonnes
• 2016-17 – 12,547 tonnes
• 2017-18 – 28,097 tonnes
• 2018-19 – 10,585 tonnes
• 2019-20 – 7,989 tonnes
• 2020-21 – 21,223 tonnes
• 2021-22 - 9,371 tonnes 
• 2022-23 - 13,294 tonnes 
• 2023-24 - 7,821 tonnes 

If the treatment has been undertaken, why is there still snow and ice on the road?

Treating the roads and spreading salt does not guarantee that the roads will be free from ice and snow. Salt requires the friction of the traffic to work it through the snow. Salt works by reducing the freezing temperature of water. Snow and ice are solids that need to be broken down/melted by traffic movement. On quiet roads, there may not have been enough traction to ‘activate’ the salt.

Our larger gritting lorries can be fitted with snow ploughs and are used as required to remove the heavy dumping of snow from the roads. The plough must have a clearance above the road to protect the road surface and to ensure the vehicle can manoeuvre around. This does leave a layer of snow on the roads. No guarantee can be given that roads will always be completely clear of ice or snow.

What's the duration of a treatment?

We aim to complete each grit run within 2.5 hours. This is timed from the depot gates to the end of the gritting route.

What should I do if a salt spreader was travelling too fast to be safe?

Contact the Customer Service Centre on 0345 606 6171 and tell us when and where this happened, and we will investigate your concerns. When spreading, salt spreaders should travel at no more than 35mph.

How many miles do Suffolk Highways treat?

Approximately 1,259 miles / 2,015 kilometres on our Priority 1 routes

Approximately 843 miles / 1,349 kilometres on our Priority 2 routes.

Does Suffolk Highways carry out private gritting?

Suffolk Highways does not undertake the salting of private roads or non-highway areas except in exceptional circumstances where there are a high number of vehicle movements to an individual location such as a hospital or bus station.