Gritting and winter maintenance Q&A

By on 14/01/2013 in Factsheets, Winter Alerts

What routes do we treat?

Winter Maintenance is divided into three priorities:

Priority 1 - Strategic Routes Hierarchy

Priority 2 - Main Distributor Hierarchy

Priority 3 - Secondary Distributor Hierarchy

  • Emergency service preferred routes
  • Frequent Bus Routes (30 minutes or less)
  • Housing Estate Access Roads

National guidance suggests that certain roads should be treated, for example major roads in the city, bus routes and routes identified by the emergency services - these roads are known as the Priority Treated Network.

This Priority Treated Network in Birmingham, covers 1,200km (750 miles) and makes up almost 50% of the total length of all roads within the city. These roads are identified by a number of factors, including major roads, bus routes and routes identified by the emergency services. The routes are designed to ensure so that they are gritted as efficiently as possible. Pavements are also gritted where they are a priority, such as in the city centre.

Local volunteers from the Open Street Map project have kindly mapped gritting routes onto their map. While we can accept no liability for any errors, we’re very grateful to them for their contribution.

You can view the gritting map by visiting: http://mappa-mercia.org/gritting-map.shtml

How many roads are treated?

In Birmingham, this network covers approximately 1200 kilometres (750 miles) - nearly 50% of the total length of all roads within the city. This is about the same distance as it would be to drive from Birmingham to Berlin!

How many gritters do we have?

Amey, in partnership with Birmingham City Council, launched its winter maintenance service on 1 October 2012. This year, the service will use a fleet of 25 gritters with snow ploughs which are on 24-hour standby, seven days a week. The gritters are only one year old. There is also the possibility of calling in spare vehicles from a central Amey hub if needed.

How do we monitor the weather and decide when to grit?

A team of specialists co-ordinate the service, constantly planning gritting operations, monitoring weather conditions and sending out gritters when necessary. The new gritters use GPS technology as well as a system which records when, where and how much Amey has gritted the roads. This provides valuable information regarding salt levels, which are constantly monitored, to plan future gritting operations. The level of salt in storage is constantly monitored to ensure stocks do not run low.

What do we grit with?

We grit with rock salt mined from underground and crushed to resemble light brown gravel. Once spread and ground by traffic, it appears white on dry roads.

How many snow ploughs do we have?

One for each gritter plus 14 spares.

Which roads are ploughed when there is heavy snow?

The highway network for snow clearance of carriageways is based on the precautionary salting network. Therefore carriageways will be ploughed and cleared of snow in the same priority order as they are salted. All priority 1 and 2 roads will be ploughed until snow stops and the roads are deemed clear.

How do we determine there is enough snow to make ploughing necessary?

Ploughing is required when more than 30mm of snow is already lying on the carriageway and it is likely that temperatures will remain below zero or more snow will fall.

How often do we treat roads?

We typically grit 40-50 times per year but this varies depending on weather conditions.

When do we treat roads?

Planned gritting takes place on nights when ice is predicted on road surfaces. We try to avoid gritting during rush hours. Reactive gritting is undertaken in response to accumulations of snow and ice during very severe weather.

How many grit bins do we have?

Currently, 1260 grit bins are provided across the city as an aid to road safety rather than as an aid to free movement of vehicles. They are an additional measure to gritting with gritters and are not an alternative to the gritting of the conventional routes.

Who can use the grit bins?

They are provided as a self-help facility for road users, usually near places that could be hazardous – such as busy junctions, steep hills and sharp bends. The salt is for use on the public highway only. It is not for private areas such as drives and garden paths. Rock salt is widely available from DIY stores and builders merchants for private use.

During what period are the gritters ready go out?

  • The winter maintenance programme operates between the beginning of October and the middle of May each winter.
  • A fleet of gritters is on 24-hour standby, seven days a week.

How do we know there is enough salt on a road or more salt needed?

  • We have fitted all of our gritting fleet with GPS technology together with a system that electronically records when, where and how much Amey has gritted the roads. This provides valuable information regarding salt usage to help plan future gritting routes.
  • We also operate a road weather monitoring system that provides salt measurement readings on the road network.

How long does it take to grit all of the roads we treat?

Within an hour of call-out, gritters are fully loaded and on the road. It takes 3-4 hours to grit the whole of the priority network in Birmingham. Difficulties can arise when roads are obstructed by traffic or parked cars.

Who do we work with to ensure the best results?

  • There are Seven Urban Authorities within West Midlands conurbation: Birmingham, Coventry, Dudley, Sandwell, Solihull, Walsall and Wolverhampton. Icelert displays the sites of seven authorities plus HA Area 9. A Forecast Service is provided by MeteoGroup (Contract with Dudley MBC on behalf of all Seven West Midlands Authorities who then share the costs). This ensures we have relevant assistance/easy liaison in poor weather conditions. It also enables us to compare policies, plans and the recognise a need for joint press statements if necessary.
  • We also use the Twitter hastag #wmgrit bringing together relevant tweets from across the region.

What is Icelert?

  • Iclert is a road weather monitoring system which the West Midlands was one of first areas to use. There are 27 Icelert outstations owned by seven West Midlands Authorities across the region plus those owned by HA Area 9.
  • A messaging system is used to inform neighbouring authorities and emails and SMS messages are automatically generated.

How does grit work?

Salt lowers the freezing point of moisture on the road surface. It helps prevent ice from forming and melts existing ice or snow. If it rains, the salt is washed away and roads need to be re-treated. In very cold weather (below -6°C) even salt will not prevent roads from icing.

How does snow affect the salt?

  • Salt is spread before snow fall. It will not stop snow settling, but helps prevent snow sticking to the road surface and so speeds up melting with the action of car tyres moving over it. During continuous snow fall more salt is spread to reduce the depth.
  • We are able to plough deep accumulations of snow but for every 50mm that falls in Birmingham, 1.4 million cubic metres of snow has to be cleared. That's enough to fill 22 Rotundas!

What happens if streets are swept after the road has been gritted?

  • In the case of severe weather, some services, such as street cleansing, will be suspended to avoid the salt being cleaned off the roads.
  • Text messages which are automatically generated and sent informing key Amey and Birmingham City Council staff of gritting, are also used to text sweeper drivers to ensure sweeping is not undertaken following salting operations.

Can residents request their road be gritted in the event of bad weather?

During severe weather we receive lots of residents asking for their roads to be gritted - please remember that it is not possible to grit every road or footway in the city. Work has to be prioritised and private and/or unadopted roads are not treated.

Which pavements are gritted?

  • Pavement gritting is focused on areas where it is most needed, such as the core of the city centre and other major shopping areas.
  • When severe weather conditions persist, every effort is made to clear snow from pavements around shopping centres, hospitals, and railway stations.

Why do more potholes appear during very cold weather?

  • Potholes form more quickly after periods of snow and ice. Long periods of freezing weather can cause a continuous 'freeze/thaw cycle' that puts deteriorated road surfaces under extreme stress. Water gets into cracks and holes in the road surface which then freezes and expands - causing potholes to form.
  • Once a pothole forms, it can rapidly grow through continued traffic driving over and dislodging more and more road surface. If a pothole fills with water the growth may be accelerated as the water washes away loose particles of road surface as vehicles pass. Badly formed joints in utility company trenches can fail and lead to potholes even in relatively new surfaces.

What are we doing to prevent and repair them?

The work is carried out on a worst-first basis, and the programme will mean that large volumes of potholes will become a thing of the past on Birmingham's roads. Safety is always our priority – some of the factors in determining the severity of a pothole are the size and depth of the hole and the volume and speed of traffic on the affected road.

A team of highways inspectors, enquiry officers and highways stewards, our eyes and ears on the streets are all responsible for locating and identifying potholes and other problems on the road. Our dedicated teams operate 24/7, 365 days a year. If the pothole presents an immediate danger to the travelling public it is passed directly to an Incident Response Vehicle crew who will attend and 'make safe' within the hour. These potholes are then included into a planned maintenance programme to allow permanent repairs to be carried out usually within 28 days.

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  1. Naomi Jones says:

    Hello
    After reading the above about the gritting arrangements for Birmingham & Sutton Coldfield, I appreciate the work of the Council gritting team
    However could I request that Abbey Road, Stockland, B23 be considered for gritting please. This is a steep road, with hazardous driving conditions when it snows. The snow never seems to melt on the road.

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