Generally, the winter maintenance season lasts from October to April, during this period arrangements are made to ensure that highway authorities are able to respond to any weather conditions at any time, but preparations are started long before the winter is upon us:
• The vehicle fleet is maintained throughout the year to keep it in good condition
• Drivers are trained and familiarised with their treatment routes
• Decision-makers are trained by weather forecast providers to help them make the correct decisions
• Duty rotas are drawn up to ensure 24-hour coverage
• Simulation exercises are carried out across the country to emulate severe weather to ensure all the communication processes and decisions are tried and tested before the first frost of winter
• The salt is ordered and stockpiled in the depots
Required Resources
In order to provide an adequate winter maintenance service throughout the winter season, highway authorities need resources including:• Winter maintenance vehicle fleet fitted with snow ploughs
• Loading facilities or vehicles
• Snowblowers for extreme conditions
• Sufficient drivers to provide the service for 24/7 cover
• Increasing usage of Global Positioning Systems fitted on the vehicles
• Data loggers to monitor salt usage
• Decision making staff
• Depots with salt stock management systems
• System of weather stations on the network to monitor conditions
Highway Authorities have a duty under Section 41 (1A) of The Highways Act 1980 to ensure, “so far as is reasonably practicable, that safe passage along a highway is not endangered by snow or ice”. Highway Authorities achieve this by treating carriageways with an anti-icing agent. It is important to note that, apart from trunk roads and motorways, not all roads within the UK are treated to prevent ice formation.
The cost and the effect on the environment would be too prohibitive. Routes that require treatment are determined traditionally by class of road and traffic usage, but, under the new legislation, highway authorities are required to undertake a risk assessment of the whole of their network. Once decided upon, treatment routes are designed to ensure that the treatment time does not exceed pre-agreed times.
A Snow Forecast
On the forecast of snowfall highway authorities will instigate a number of measures. Some highway authorities may set up special “snow desks” to allow the co-ordination of resources when dealing with the event. Immediately prior to its arrival, salt will be spread to ensure that the network is kept as free from snow as possible. The vehicle fleet will be fitted with snowploughs and operatives will be placed on stand-by. On the arrival of snow, the fleet will be sent out to spread more salt and start to plough any snow accumulations on the network. In extreme cases where snow has accumulated to considerable depths, dedicated “Snowblowers” may be used. Work will continue until the network is completely cleared.
Road maintenance duty officers are able to obtain almost real-time data transmitted from the weather stations located at various locations adjacent to the road network. Weather information can relate to:• Road Surface Temperature
• Air temperature above the road surface
• Dewpoint (humidity of the air)
• Wind speed & direction
• Road state (dry, wet etc)
• Sensors in road that can detect the level of salt on the road
Once armed with this information winter maintenance officers will use their experience and knowledge of their network to make a decision as to what action to take. In general every effort will be made to ensure that treatments are timed so that salt is spread on the network prior to the formation of ice.
Environmental Issues
The HTMA are committed to optimising winter maintenance practices in order to protect the environment. As with all highway maintenance activities, there are environmental implications from winter road maintenance. Highways depots, spreading vehicles and the de-icing agent all contribute, but with good management this impact can be minimised