Have you ever wondered how we help keep Derby moving during chilly winter months? This page has everything you need to know about our gritting operations.
Despite the name, gritting rarely involves grit (a mix of sand and stones) at all. Gritting involves spreading rock salt onto roads and pavements to prevent ice forming or to help melt snow and ice.
In Derby, we grit roads using rock salt which has been coated in molasses. The molasses helps the salt to dissolve quicker and stick better to the road surface, making it more effective than uncoated salt.
When the salt dissolves in surface water (helped by vehicle and foot traffic to crush it) it lowers the freezing temperature of the water. Instead of freezing at 0° any moisture freezes at -6° to -8°.
As Highway Authority, we are responsible for keeping roads safe. This includes a statutory ‘duty to ensure, so far as is reasonably practicable, that safe passage along a highway is not endangered by snow and ice’ (Highways Act 1980).
Our primary gritting routes include:
If there is prolonged heavy frost, ice or snow then we will consider treating other roads on a priority basis. This depends on resources being available as our priority is the primary routes.
Pedestrianised areas and footpaths in the city centre and shopping centres will also be treated when the forecast indicates that rain is likely to be followed by freezing conditions, or when snow is forecast. This treatment will normally be carried-out outside normal shop opening times.
The salt is spread evenly on to the road surface using our fleet of gritters. We spread anywhere between seven and 30 grams of salt per square meter of road (depending on weather conditions).
When icy conditions are forecast we will grit the primary routes in Derby as a precaution.
We use six gritting vehicles and have one on standby. We can have these vehicles on the road within one hour if the forecast changes.
The weather forecast is checked at least once a day throughout winter (between 1st October and 30th April).
Our forecast provider, MeteoGroup advises us of the possibility of freezing road surface temperatures, ice or snow and gives an approximate time when we might expect this to happen.
As well as being updated with regular national forecasts and local information for nearby weather stations, we monitor a network of sensors embedded in roads across Derby. Each is connected by cable or mobile phone technology to our automatic weather station (grey box by the roadside) and measures road and air temperatures, rain, dew and salt levels.
The sensors are sited either on a representative stretch of road (no nearby trees, buildings or bridges, which offer some protection from the cold), or traditional cold spots. The weather stations then beam back information for us to monitor.
All of this information helps us decide if we are going to grit the roads. Most of the time, we treat roads in the early morning or late at night when there is minimal traffic on the roads and before ice can form.
Our snow clearing operation will take place when heavy and continuous snow settles. We can quickly attach snow ploughs to the front of our gritting vehicles so they can clear roads and grit at the same time. Snow ploughs only work effectively when snow is more than 3-4cms deep; they cannot work on roads that have road humps or similar traffic calming measures.
We concentrate on primary routes such as access to hospitals, fire and police stations and other important facilities whilst it’s snowing or if there are strong winds causing drifting.
Once the main roads are clear, we will begin to work on other roads.
It may not be possible to clear every road, and some roads may have to be left to thaw naturally as our vehicles cannot fit down narrow roads.
Highways England clears motorways and trunk roads, such as the A61, A38 and A6 in Derby. Derbyshire County Council clears all roads in the county from the city/county boundary. You can see who is responsible for roads on our gritting route map.
Find out where your nearest grit bin is located using our map.
Grit bins have been provided to allow residents to help spread salt on the roads and footways in their neighbourhood that aren’t part of our gritting routes. It should not be used on private driveways and footpaths.
We aim to keep all of our grit bins full as far as possible. If your nearest grit bin is empty during cold weather, please call Streetpride on 0333 200 6981 (9.00am to 3.00pm, Monday to Friday) and we will re-fill it for you as soon as we can.
The government website provides advice on how to clear snow and ice on the road, path or cycleway safely. This is especially useful if you live in an area that is not routinely gritted by us.
Winter can present some very difficult driving conditions.
Everyone should consider having an Emergency Winter Kit in their car. Carrying the following items could be lifesaving if you were to become stranded: