We grit the highway network to help the safe movement of all highway users: buses, cyclis ts, motorists and pedestrians. It is important in terms of both road safety and economy.

With 797 kilometres (or 495 miles) of highway it would be expensive to grit the entire network.

310 kilometres (or 192 miles) of highway are therefore prioritised and gritted. We spread grit to prevent ice from forming every night when the Metrological Office forecasts frost or icy conditions. 

How and when?

Our aim is to ensure that salt is spread on the highway before ice forms. We achieve this by dividing the borough into five routes and use a fleet of five gritters to cover the pre-identified routes. These gritters spread a total of 1700 tonnes of salt during an average winter (October - April). We aim to have a response time of one hour for the contractor to arrive and load the vehicles. The gritting operation is normally completed within four hours from the time gritting commences.

Which roads are gritted?

In determining which roads are gritted, there are two types of gritting routes - primary and secondary. When the road surface temperatures are forecast to go below freezing with ice or frost expected, the primary routes would be treated. These routes meet the following criteria:

• main roads
• roads servicing hospitals, ambulance and fire stations
• roads servicing comprehensive schools
• bus routes with three or more buses in an hour.

The motorways M62, M56 and M6 are the responsibility of the Highways Agency

The secondary routes will be treated after periods of prolonged ice or snow, but only when the primary routes are considered to be safe. The secondary routes are made up of the following roads:

• roads servicing the hospice
• roads service industrial estates
• roads with less than three buses per hour
• roads servicing primary schools.
  

Where do we place grit bins?

We try to place grit bins across the borough in vulnerable locations where the roads do not meet the required criteria to be included onto the primary gritting routes. Priority has to be given to steep inclines that lead onto or from major road junctions. The intention is for the grit to be used on the footpaths and roads and not on private driveways. Any locations where members of the public have requested the placement of grit bins will be inspected and appropriate action will be taken. It is not possible to make a general provision of grit bins for use by residents in suburban areas, because of the high cost involved and the financial constraints.

After periods of adverse weather the contractor is instructed to check and replenish grit bins as necessary.

Grit bin locations.pdf

Weather forecasting and decision making

The Meteorological Office provides us with weather forecasts as part of their open road-forecasting bureau. The forecasts form part of our ice prediction system, which is monitored 24 hours a day during the winter period. The system downloads data from the two weather stations based within the Warrington area. The following information is provided:

• text of expected weather and road conditions
• forecast graph of air, road surface and dew point temperatures and thermal map imaging of the borough's roads
• graph of actual temperatures
• two to five day forecasts
• status table of both road sensors.

Before the weather stations were installed a team of specialist consultants conducted a survey of the borough in consultation with the Met Office to determine the most appropriate locations. The study determined that Winwick and Daresbury were considered to be representational of the weather experienced throughout the borough. Therefore a monitoring station (at Winwick) and a forecast station (at Daresbury) were installed to provide specific information for the borough.

The information is used by the Met office to prepare weather forecasts to aid our decision making process. Decisions to treat roads are taken carefully to ensure road safety, but also to avoid unnecessary gritting. The Daresbury forecast station has been installed in partnership with Halton Borough Council. We also have access to a number of monitoring stations throughout Cheshire, this is a valuable tool to aid the decision making process and to build up a clear picture of the weather for the whole of Cheshire.

Rock salt

This is used as our anti-icing material. Our gritting fleet spread the salt onto the highway at spread rates between 10,25 and 40gm/sq m depending on the forecast road surface conditions. 10gm/sq m is normally spread in anticipation of ice forming and 40gm/sq m is used in anticipation of snow or if we are trying to clear a build up of snow or ice 25gm/sq m would be used after long periods of rain, or where the road surface is particularly saturated to prevent ice from forming. We need to spread salt accurately as it comes from a non-renewable source and, in high concentrations is environmentally unfriendly and can damage vegetation.

Salt works by turning the ice or snow surrounding each granule into saline solution. The action of the traffic is essential for salting to be effective by breaking down the salt granules to form a saline solution to prevent ice from forming or to melt it. 

Cycleways and footpaths

Cycle ways are gritted when they form part of the carriageway network that meets the required criteria. Footpaths alongside carriageways and other cycleways are not treated as part of the primary gritting routes. The financial resources available for winter services are not sufficient to allow for treatment of all cycleways and footpaths. Routes are reviewed on an annual basis.

Town centre and shopping areas

During prolonged periods of ice and snow, extra resources will be deployed to grit footpaths in the town centre and outlying shopping areas. Consideration will be given to all requests for gritting and will be actioned dependant upon individual circumstances.

Clearing snow yourself

There is no law stopping you clearing snow and ice on the pavement outside your house and to assist you with this, advice can be found by clicking this link.

How to drive safely in extreme weather

Extreme weather conditions and icy roads can make driving more difficult, especially in winter. By following the Highways Agency's advice you can help to make your journey safer and reduce delays for everyone. See the driving safely link.

How can we get it wrong?

No matter how accurate the forecast, there are situations where we cannot salt the network prior to icy conditions. Such situations are:

• when rain is followed by rapidly clearing skies, salting will start after the rain has stopped to avoid the salt being washed away.  Temperatures can fall as much as 5 degrees C per hour and the wet roads may well freeze before we have time to grit them.
• dawn frost occurs on dry roads when early morning dew develops, falls on a cold road, and freezes on impact. It is impossible to forecast with any accuracy where and when it will occur.
• rush hour snowfall. When rain turns to snow coinciding with the rush hour, early gritting cannot take place as it would be washed away and gritters cannot make progress through the routes due to traffic congestion. We will always grit the roads to remove ice however, this is not ideal and the grit takes longer to act once ice has formed.

Note

It is worth noting that a change in legislation has meant that the 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 takes its winter maintenance activities very seriously and will continue its gritting procedures, with no intention of reducing the amount of roads on the gritting routes.  However, the nature of the operation means that the council cannot guarantee that having gritted, roads will automatically be free of ice or snow.

Paramount in any wintry conditions is the need to drive and walk within the conditions that prevail. (Highway code rules 205 and 206).

Winter Statistics 2010/11

From October 2010 to April 2011 Warrington Borough Council carried out 59 gritting runs, with a total of 24,513 km being driven. The amount of salt used on the gritting of authority roads was 2400 tonnes.

Issues and problems

To report an urgent problem or issue please call the customer contact centre on 01925 443322.

Winter Service Plan 2011-12.pdf