By Bill Heaney
During the winter months we have a fleet of gritting and ploughing vehicles on 24 hour standby and our staff constantly monitors road and weather information. Our Roads Officers use this information to prepare an action plan for the following 24 hours.
We use rock salt for winter service operations. The use of grit will only be considered when the temperature is extremely low. Rock salt has a limited impact on icy surfaces when temperatures drop below -8oC.
Our aim is to spread salt on the roads before ice forms but this is not always possible. Rainwater can freeze quickly and ice can form before our gritters have completed their routes. Additionally, if rain turns to snow during the morning or evening rush hour, traffic congestion makes it very difficult to grit roads. More information on salt and why we use it is available on our how grit works page.
Snowploughs and gritters are large vehicles that may have difficulty in clearing and treating narrow streets with tight bends and junctions. You can help by avoiding double parking or, if possible, parking your car off the road.
In extreme conditions or if you are concerned about road conditions – don’t travel. Allow the roads to be cleared first. If you get stuck attempting to drive in such conditions, our gritters won’t get through.
When do we grit?
To decide when to grit we receive weather forecasts from our Forecast Provider that include road surface temperature information along with real time information received from our two weather stations located within West Dunbartonshire.
No matter how accurate the forecast, there are situations where we cannot grit the network prior to icy conditions. Some of the situations are as follows:
- When rain is followed by rapidly clearing skies, salting will normally start after the rain has stopped (to avoid the salt being washed away). Sometimes temperatures may fall by as much as 5 degrees per hour and the wet roads may freeze before we have started or completed salting.
- “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 salting cannot take place as it would be washed away and gritters cannot make progress due to traffic congestion. We will, however, always carry out salting to remove ice, in line with the road priority. This is not ideal, however, as salting takes longer due to traffic congestion.
How do we decide where to grit?
Due to the finite resources available to the council’s Winter Maintenance Service,the Council’s roads are treated by gritting and ploughing to ensure the busiest roads are kept open and safe. Prioritisation of roads are based on their level of traffic, so we treat our strategic routes and then less important routes when resources become available. When severe weather conditions are forecast, we grit 62.7% (approx 224km) of West Dunbartonshire’s public road network.
Roads gritting priorities have been determined in the following way:
Primary Gritting Routes
Priority 1 Routes – 43.5% (Approx 156km) of public road network
Upon receipt of a marginal weather forecast (i.e. frost predicted), the Council will treat all roads of primary importance and which form a strategic network (A & B Class roads), main urban traffic routes, the main routes to schools where these can be clearly identified, major bus routes and routes to main emergency service establishments.
Priority 2 Routes – 62.7% (Approx 224km) of public road network
When severe weather is forecast (i.e. ice or snow predicted), in addition to treating the Priority 1 routes, Priority 2 routes will also be treated that include main urban spine roads into housing and industrial areas, where there are difficult bends or steep inclines and are particularly prone to icing.
Precautionary salt treatment, treatment of ice and clearance of snow operations will be carried out 24 hours per day on the primary road network (Priority 1 & 2 Routes).
Secondary Gritting Routes
These routes cover all remaining local distributor and access roads, local rural roads, prospective public roads and private roads.
Treatment will only be carried out on the secondary road network when the general outlook (established from forecasts and other weather information) is that the prevailing ice and / or snow conditions are likely to continue to exist unbroken beyond 48 hours from the initial onset
Any treatment on Secondary roads will only be carried out during normal working hours.
Primary Footway Treatment
Footway Priority treatment is normally only undertaken during normal working hours (8am – 3.30pm Monday to Friday) with priority given to:
- Urban shopping areas and pedestrian precincts
- Main routes to near Schools
- Main access routes to hospitals
- Identified public buildings
- Major sheltered housing complexes
- Public transport hubs
- Busy links between shopping centres and commercial areas
- Main pedestrian routes in major housing developments
- Main access routes to sheltered housing complexes and other establishments
- Identified day centres for older people or people with special needs
Steps and ramps to underpasses and footbridges together with any ‘low level’ footpaths associated with the underpasses and the footpaths on the footbridges will also be treated as a priority.
No precautionary salt treatment in advance of adverse weather conditions will be carried out by West Dunbartonshire Council. Treatment of ice and snow will only be instructed when the general outlook established from forecasts and other weather information, is that the prevailing ice or snow conditions are likely to continue beyond midday 24 hours after the initial onset.
Secondary Footway Treatment
The remainder of the public footway network will only be treated in exceptional weather conditions. To begin, one footway along most streets within built up areas, which best serves pedestrian traffic or serves the most premises, will be gritted/cleared of snow. Treatment will then move on to any remaining areas presenting greater difficulties than general and progressively move onto footway or footpaths of lesser difficulty. A halt to this treatment may be called at any time if, for example, actual or forecast conditions improve or for logistical reasons.
Any treatment on Secondary footway routes will again only be carried out during normal working hours.
Grit bins will be provided on non-priority 1 routes where there are:
- difficult bends
- junctions and turning areas which are particularly prone to icing and where they have been in place for a number of years (historic reasons)
- A special need has been recognised (e.g. sheltered complex, crossing patrols, steps, underpasses etc.)
- Grit bins will not be sited within 300m of another grit bin
On the conditions that:
- Local residents agree on a suitable location within the road boundary
- There is confidence that the grit bin will be properly used
On priority 1 carriageway gritting routes, grit bins may occasionally be provided for use on footways where appropriate. However, as the majority of the footways on the priority 1 carriageway routes are adequately covered under other areas of the Winter Maintenance Plan, this will be rare.
Grit bins will not be provided on un-adopted roads, whether privately maintained or prospectively adoptable. Housing Developers are required as a condition of their Construction Consent to meet these requirements.
Roads Services currently supply in excess of 480 grit bins for salt/grit storage for use on the adopted public road and footway network. The large number of bins reflects the Council’s desire to encourage self help at locations where minor roads and lesser important routes have a lower priority response for mechanical treatment.
We operate a strategy of leaving grit bins in place all year round.
Removal of grit bins
Grit bins will be removed from their given location:
- Where there is proof of misuse of the salt
- Where residents cannot agree a location or need
- Where bins suffer continued vandalism
- Where there are concerns, over the summer months, that the grit bin has an extreme effect on local amenity the grit bin may be temporarily removed at the discretion of the Roads & Transportation Manager
The provision of a new grit bin (or relocation of an existing grit bin) should be agreed through consultation with residents prior to installation, particularly those directly affected. If a suitable location, which addresses the geometric requirements, cannot be agreed then a grit bin may not be provided.
Servicing of grit bins
Grit bins will only be placed where they can be easily serviced.
Grit bins will be refilled as soon as possible after a period of extreme weather. Given the large number of bins, there is a considerable resource implication to replenish salt/grit and this task will only be undertaken when carriageway and footway treatments have been scaled down sufficiently to release labour and plant for grit bin duties. Priority will be given to the higher altitude locations.
Residents of West Dunbartonshire can also obtain small quantities (up to 10kg) of rock salt for private use from the Council’s Road Depots located at:
- Elm Road,Dumbarton,G82 2RH
- Stanford Street,Clydebank,G81 1RF
Please bring you own container to transport the rock salt.
- Rain showers followed by clear skies can cause ice to form on roads very quickly. The rain may have washed any salt off the road leaving it vulnerable to icing
- Sunrise after a clear night can cause frost to form on roads, even if it is dry.
- Black roads do not mean ice-free roads. Black ice is extremely dangerous, as it is often localised and not readily visible. It can persist or recur even after the road surface has been treated with salt
- Water running off grass verges or embankments onto the road can cause isolated icy patches to form, even if the rest of the road surface seems fine.