Does gritting melt snow

Gritting doesn't directly melt snow. Firstly it must mix with the snow to form a saline solution.

If snow is predicted:

Gritting is carried out in advance of the snow fall so both will immediately mix to create a saline solution.
This aims to reduce the build-up of snow and prevent the formation of ice.

However, in prolonged periods of snowfall:

It can fall at a rate faster than the grit can mix with the snow which means the snow will settle.
The accumulated snow will have to be ploughed away from the roads
Placing grit on top of snow, which has already fallen has limited benefits.

When do we Grit

This depends on a variety of factors. Decisions whether gritting is required are made daily and sometimes reviewed multiple times in a day.

When we know with certainly from the weather forecast that roads will require treatment we:

Aim to commence gritting at least 3 hours in advance of when the weather forecast predicts when frost or ice will form.
Aim to carry out gritting in the evening after the peak traffic period or in the early morning, prior to the peak traffic period on the road network.
Prefer to commence gritting after the evening peak period (7pm onwards) to avoid delays and ensure there is traffic to help activate the grit to form a saline solution.
Prefer to grit in the early hours of the morning we would not wish to commence after 4 am to avoid the morning peak period and potential delays.

Where the weather forecast cannot confirm with certainty that gritting is necessary, we will continuously monitor the weather data and grit only when it is determined it is needed.

Difficulties can arise when rain is forecast to fall, right up to the time of freezing or when the rain is forecast and will turn to snow. In these circumstances the gritters must wait as late as possible or the grit will be washed away.

Why a gritting vehicle may not be spreading grit

Gritting vehicles dispense the required amount of grit directly down on to the road in a fine spray that you may not see.

Sometimes a vehicle may not be spreading grit because:

It hasn't reached the starting point of its treatment route.
It is returning to the depot to refill.
It is driving on a road that is not on the gritting route.
It is driving over a section of road that has already been treated.

Every gritting vehicle is fitted with a GPS system which tracks its route, speed and location. The team monitors this data to make sure the lorries don't deviate, and their routes are being treated correctly.

Prioritising our roads

There are over 800km of adopted roads in Wokingham Borough and so we prioritise which roads we grit and when.

This is set out in the Winter Service Plan.
The roads are broken down into three levels of priority.
Some roads listed are only partly gritted.

Primary routes

These routes are the most heavily used in the borough and include most bus routes.
Gritting and snow clearance of Primary routes will be carried out based on information received from the weather forecasting service

Secondary routes

These routes will only be gritted and/or cleared of snow during particularly severe and prolonged hazardous weather conditions.
If the decision to treat the secondary network is made, then treatment will only commence on full completion of the primary routes.
Gritting will not generally be carried out on any spur roads or cul-de-sacs off the main through routes listed (even if they share the same name as those roads).

Third Tier Salting Network

Roads that will only be gritted following extreme snow events.
Roads on the list are generally the larger estate roads (but not each minor road or cul-de-sac).
Roads that may help the movement of traffic in difficult locations.
Roads with difficult gradients.
Roads that are considered to lead to significant numbers of vulnerable residents.

Areas we do not grit

Full details of our gritting routes are shown in our Winter Service Plan, but we do not grit:

Residential roads (unless they are shown on the priority list).
Footpaths (between roads)
Footways (adjacent to carriageways but see content below).
Most Car Parks (unless they are shown on the priority list).
Private property (unless they are on the priority list).
The M4 Motorway (the treatment of the M4 motorway is undertaken by contractors for National Highways Area 3).