1. Introduction

1.1. The prime aim of the service is to prevent ice and snow forming on the precautionary network and decisions are based upon achieving this objective. The decision to treat the network is made by the Duty Officer in each of the 4 Divisional areas and the City. As weather forecast accuracy has improved there is less risk involved but priority in decision-making will always be on safety rather than cost grounds. Each time the gritters are called out it costs £22,000.

2. Budget

2.1. Annual winter maintenance budget –made up of:

• Salt and other variable costs £554,000
• Vehicle and other fixed costs £577,000
• TOTAL £1,131,000

2.2. This is not a cash limited budget, but the level is set based upon a rolling 5-year average expenditure. Any over or under spends are accommodated within the Council’s overall budget.

3. Winter Maintenance Plan

3.1. Cambridgeshire has a Winter Maintenance Plan, which is used during the winter period to define the policy of the service and all the key elements to ensure that the service runs effectively.

The Plan includes:

• Operations Plan
• Precautionary Salting
• Snow Conditions
• Weather Forecasts
• Plant/Equipment
• Training
• Public Relations
• Client Responsibilities
• Contractor Responsibilities
• Decision Making

4. Winter Maintenance Fleet

4.1. We have 35 gritters, and we grit over 1000 miles of our roads – 42% of the network, which is well above the national average. These aim to include:

• Primary routes and main distributor roads
• Roads which carry the heaviest early morning traffic
• Roads that link centres of population
• B and C class roads adjacent to fen drains
• Roads that link salted routes with those of adjoining counties.

4.2. We also have a number of farmers who have our snowploughs who, during snow conditions to supplement our gritting fleet.

4.3. If roads are blocked, we have details of excavators who can be employed to assist in digging out blocked roads.

4.4. The Highways Agency, though their maintenance contractors, are responsible for salting the trunk roads in Cambridgeshire (A14, M11, A1, A1M, A47, A428).

5. Salt Stocks

5.1. Salt is stored at seven highway depots around the county, which totals 12,000 tonnes, including Cambridge City, and is enough for 60 runs. Stocks are reviewed regularly during the season and can be replenished quickly if necessary.

6. Weather Forecasts

6.1. During the winter Cambridgeshire County Council employ weather consultants PA Weather Centre to provide a number of forecasting services.

• Daily 24-hour detail forecast sent out every lunchtime to each Divisional Office with details of the weather forecast for the following 24 hours predicted road and air temperatures and a confidence factor on the forecast.
• A 5-day summary forecast with details of the forecast weather for that period.
• Regular updates during snow or unpredictable periods
• 24 hour access to a forecaster
• An abbreviated weather forecast and actions are available on the County Council web site.

7. Salt Action

7.1. As snow falls onto a gritted road, there will be some melting, but if the snow intensifies or the road has limited traffic, the snow will settle on the road and if temperatures then drop to below freezing a crust of ice will form.

7.2. Where there is traffic, the tyres mix the salt and the snow together and will break up the snow and stop it from compacting into ice. A sign of salt is when the snow is a dirty brown or black colour.

7.3. Where snow has settled on a salted road, once traffic flows again, the salt trapped below the snow will readily break down the ice.

8. Sequence of Forecast Events Leading to Thursday 30 January

8.1. From the 5 day weather forecast on Sunday 26th January it was known that snow was expected from Wednesday / Thursday but timing was not certain.

8.2. The 24-hour weather forecast received Wednesday showed that snow was expected overnight 03:00 – 12:00 when the next forecast period started.

8.3. Whilst PA Weather Centre were able to forecast the snowfall, predicting the likely time it would arrive in Cambridgeshire was rather more difficult. Due to this uncertainty we were in regular telephone contact with the forecaster during the morning to keep up to date on developments.

9. Based upon this forecast, the following action was taken

9.1. All Divisions and the City Council salted on Wednesday evening with a spread rate of 20 gms per sq m. This was further supplemented with another salting run at 0400 hours on Thursday at a spread rate of 20 gms per sq m. Cambridge City felt that they had enough salt down for their urban roads and did not undertake the second run.

9.2. Following discussions with PA Weather Centre Ltd on Thursday morning, they confirmed that the first snow would arrive probably mid-afternoon.

9.3. All drivers were instructed to report to their depots at 1300 hours to fit snowploughs, load up and salt. Salting continued throughout the afternoon and night until Friday morning. As the main precautionary routes were cleared the gritters were then sent to treat secondary routes.

9.4. Certain agreed footway routes were also salted on Friday morning.

9.5. Two farmers were deployed in West Division to assist in ploughing roads affected by drifting. Two diggers were commissioned in East Division to assist where snow had filled cuttings in the Newmarket area.

9.6. Cambridge City salted their precautionary routes on Wednesday evening, as the County, but then did not salt again until 1800 hours on Thursday evening, but were hampered by traffic. They continued through the night and had the City’s roads clear by 0600 hours Friday morning.

10. Further Action

10.1 After a full day of salting on Friday, a further full salt run was undertaken on Friday evening. The forecast for Saturday morning was for freezing rain so A further salting run was undertaken at 0300 hours. Further salting runs Were undertaken on Saturday and Sunday evenings.