Snow clearance on carriageways is carried out on a priority basis.
Ploughing is the most effective method of dealing with snow and ploughing aims to clear the snow from the road surface back to black. Before snowfall a 40g/m² pre-treatment will take place across the entire precautionary network to provide a de-bonding coat of salt and assist future ploughing operations.
Ploughing will start as soon as practical on the network where conditions allow, with each pass supplemented by salt or salt / grit mix treatment.
In urban areas, where ploughing is impractical, repeated applications of salt / grit mix can be used to remove heavy accumulations of snow.
During prolonged snowfall it may be necessary to plough continuously to prevent build up and compaction of the snow by traffic. However, once the depth of snow exceeds 100 - 120mm, or on steep gradients, it may be necessary to plough without salting to aid traction.
Heavy and prolonged snow
During very heavy, prolonged and county-wide snowfall it is not normally possible to keep all of the precautionary salting routes free from snow - Dorset Highways will need to focus resources on clearing and treating the priority ploughing network of key north-south and east-west routes.
The need to run two vehicles on these routes, one to plough the other salting/gritting, reduces capacity to treat the entire network. The aim is to keep these priority routes clear and move on to clearing the rest of the precautionary network.
Extra resources, such as ploughing contractors, will be deployed at the earliest opportunity to assist in clearing routes. Other routes will be ploughed and treated as directed by the Duty Engineer.
This operation accepts that, at times, some of the precautionary network will become impassable but by concentrating on principal routes some traffic movement can be maintained.
Community Link Network
Following a forecast of settling snow the community link network will be pre-salted at 20-40g/m² dry salt.
After snow, the network will be ploughed and salted as soon as resources become available, either by Dorset Highways or by nominated contractors. Repeated ploughing and salting will take place when resources are available.
When priority routes are clear, resources will be directed to clear the rest of the precautionary salting network. This will be followed with clearing the community link routes.
Snow clearance of some minor routes is carried out by local farmers and contractors under agreement with Dorset Highways. Snow clearance on other minor routes will be carried out as resources permit.
Residential roads and cul-de-sacs will be left to thaw naturally.
Snow clearance on footways and cycleways will only be carried out by Dorset Highways if resources are available. Some towns and parishes will carry out clearing of priority footways, including shopping areas and other well used paths.
Priority ploughing network
- A37 - A35 Monkeys Jump to Somerset boundary
- A30 - Shaftesbury to Yeovil, Somerset boundary
- A35 - Bere Regis to Holes Bay Roundabout
- A354 - Easton Square, Portland to A35, Tesco Roundabout
- A354 - junction A35 to Blandford
- A354/A350 Blandford Bypass
- A354 - Blandford to Wiltshire boundary
- A350 - A35 Bakers Arms to A31 roundabout
- A350 - A31 roundabout to A354 Blandford
- A350 - Blandford to Shaftesbury to Wiltshire boundary
- B3073 - A35 to Blackwater Junction
- B3073 - Blackwater Junction to A31 Canford Bottom Roundabout
- A348 - A31 Tricketts Cross to Bear Cross Roundabout
- A352/A351 - Dorchester to Wareham to A35 Bakers Arms Roundabout
- A353 - A352 Warmwell Roundabout to Weymouth
- A3066 - Bridport to Misterton, Somerset boundary
- A356 - junction A37 to Misterton, Somerset boundary
- A352 - A37 Charminster to A30 Sherborne
- A3030 - A352 Sherborne to A357 Lydlinch
- A351 - Swanage to Wareham
- A357 - Blandford to Henstridge
- B3081 - Shaftesbury to Gillingham to A303