Highways England has helped push winter service forward, developing ground breaking data systems, supporting research and implementing greater collaboration with local authorities. Transport Network gets the latest on how the strategic road network operator is helping beat the cold and share its knowledge.
What exciting news does Highways England have in the winter service area?
We’re obviously not the only ones to experience severe weather so we’re currently developing a research programme with European groups, roads bodies and academia to see how we can best share good practice. We’re also trialling some different weather station and sensor technology. Some of these will appear on gantries. We’re also looking at using high performance de-icers at vulnerable locations and looking at how we can adapt our equipment to continually improve performance.
It has been over a year since the implementation of your Severe Weather Information Service (SWIS), which consolidates your three major data streams for winter service into one digital platform. Can you give us an update on the system?
The SWIS system has been used for the last two winter seasons and is performing well. It’s a one-stop shop which enables operational staff to save valuable time on their daily tasks by having all the relevant information in a single place.
It has allowed people to use just one system for the majority of their tasks. As the system pre-populates data into reports, it both saves time and increases accuracy.
How has the system been updated?
The system has been updated to give better information about our vehicles on the network. We can see the current location of all vehicles for a certain area, as well historical journeys.
It allows users to change vehicle details themselves, which has streamlined the creation of reports, as fewer manual adjustments are needed. It is possible to select results on a vehicle-by-vehicle basis at the time of report creation.
A feature has also been added allowing a single point of access for Highways England staff to manage maintenance of Environmental Sensor Stations (ESS) and inform users of any actions carried out.
What does Highways England see as the future of winter service delivery on the SRN?
Looking at our own experience and that of others, coming for example, from the World Road Association World Winter Congress in Poland, it is clear we are in a good place to be able to enhance our winter service delivery and management.
We believe the focus needs to be on enhancing our weather station and sensor assets to improve our forecasting on individual routes, increasing training, and developing our capability to use a fuller range of liquid treatment options.
Can you give us an update on your work with local authorities in winter service?
We work closely at a local level with councils on winter service activities; at a national level we support the National Winter Service Research Group (NWSRG), funding mutually beneficial research projects and the development of practical guidance.
In relation to severe weather planning, we invite local authorities to participate in various pre-season severe weather events and exercises. Local authorities also contribute to severe weather event debriefs in order to share lessons learnt and to review opportunities for mutual aid.
Can you give us an update on your approach to salt storage?
We have the capacity to store around 300,000 tonnes of rock salt. We routinely monitor stock levels during the winter period and review our stock levels every May, resulting in regional plans setting out restocking activities during the summer.
We aim to start each winter with a stock between 280,000-290,000 tonnes. This is held in salt barns in over 120 depots located around our network. In all but a couple of locations all salt is stored in dedicated salt barn facilities.
During winter we monitor salt stocks very closely, ensuring all areas remain above their reporting thresholds, and that resilient stock levels are held. For the winter of 2017 -2018 we used over 330,000 tonnes of salt, with our lowest national stock level around 127,000 tonnes. When stocks get down to the reporting thresholds automatic reordering commences; however experience shows reordering often starts far earlier.
On asset delivery contracts Highways England purchases all salt using the ESPO salt framework. We also have 92,500 tonnes of salt available from within the national salt reserves, held in Highways England’s purpose-built facilities.
Can you give us a rough idea of the proportion of de-icer, brine, salt and pre-wet salt that you use? Is this likely to change over time?
Highways England’s preferred treatment option is pre wet (FS30). The decision to use either pre wet or dry treatments is made on a daily basis, based on the forecast and current or expected road conditions.
Highways England has its own fleet of 437 winter service vehicles, and together with contractor vehicles a total of more than 530 winter service vehicles and ploughs are available. Our depots have the capability to store over 1.7 million litres of brine. All depots that undertake pre wet treatments will also hold a small stock (50 - 300 tonnes) of marine salt for use in brine production.
Of the Highways England fleet, 16 are ‘combi’ vehicles, which can also carry up to 2,000 litres of liquid de-icer material in addition to salt and brine. There are also two dedicated liquid only vehicles. Our usual alternative material is potassium acetate, which we use on sensitive structures such as the Severn Crossings, Avonmouth Bridge, and the A12 Bascule Bridge. We can store around 215,000 litres of potassium acetate. Within our Severe Weather Plan, we have the ability to use other materials such as calcium chloride and magnesium chloride where conditions dictate a benefit over and above that of dry salt or pre wet salt treatment.
Are there any major differences in your approach to winter service between the North and the South of England?
We’re ready to tackle severe weather whenever and wherever it happens. We have well-developed severe weather service requirements and undertake annual lessons learnt activities to ensure we review and embed any best practices into our guidance. Our winter service routes are designed to ensure 100% of our network can be treated on a precautionary basis as and when required. In snow conditions we aim to keep at least one lane running on all of our network. We have provided specific lane availability requirements and timescales for which all lanes should be made available for traffic.
I understand you will be working with the NWSRG on some new research?
One of the key areas of winter service research, for both the NWSRG and Highways England, is residual salt measurement, which looks at a range of things including the retention of salt based on the road surface type. It also involves the use of sensors to measure how much salt remains on the road. Although this is at an early stage of development we are looking to undertake research, exploring a number of exciting new directions, with a wider collaborative group of national road authorities and European winter research groups.
We realise that the current funding system available to the NWSRG is limiting the group to smaller scale research programmes. To achieve ground breaking, operationally useful and transferable residual salt research, which will in turn lead to greater resilience and a step change in de-icer management, Highways England and the NWSRG will need to collaborate with and support larger research programmes, leveraging the expertise and funding streams of pan-European and academic programmes.
Cold Comfort 2018, the 27th Annual Winter Maintenance Conference and Exhibition, takes place at the Ricoh Arena, Coventry on 16 and 17 May. To register click here.