Solutions as dynamic as the weather


Local authorities are entering a new era as they develop a risk-based approach to winter service under the highways code of practice. So will automation provide all the solutions, or do we need more real-time control?

At Transport Network's Cold Comfort event in May. A Highways round table debate under Chatham House Rules, in partnership with leading gritter manufacturer Aebi Schmidt, looked at how the combination of automated gritting and better weather forecasting could change the nature of winter service.


It’s fair to say in today’s society it is all about data.’ So began the 2017 Cold Comfort round table. The importance of robust data in winter service is well known, both in terms of helping make decisions and in justifying them. ‘Once you produce the data the claims go away,’ said one attendee. ‘The claims only win when we don’t have the paperwork.’

However, with cheaper sensors and more sophisticated on-board software coming on the market, capturing data is becoming less of a problem than interpreting it. Add in the new risk-based approach to highways management and it is easy to feel that winter service just got harder not easier.

Addressing the current state of the technology, one attendee argued that we are coming from a world of automated spreading based on a fixed plan with pre-determined gritting routes, to a world of dynamic spreading.

New control systems on gritters from the likes of Aebi Schmidt use a two-way system that can take in data as well as display it and open it up to interpretation, allowing more dynamic decision-making. One attendee said:

‘It’s about creating a platform that can ingest all the data and allows the user to process it in the easiest way.’

The sector has gradually developed from domain-based through to route-based forecasting and now has the potential to implement gritting based on dynamic thermal mapping, another attendee said. While this development is still in its infancy, it provides an interesting fit with the risk-based approach.

A first step towards more dynamic gritting could come in the form of ‘sub-route treatments’. One attendee said this had allowed his authority to target areas of high ground during a recent cold snap. However, he warned there were some major concerns when it came to truly dynamic gritting.

‘There is the capability of doing selective treatments within routes and dynamic routing. I have two concerns - the first is can we guarantee that the drivers are going to do things in the right way so we don’t blow a hole in the savings we are trying to make? Secondly, how good is the forecast? If the forecast changes, you are negating the savings because you might have to go round a route and do the bits you have not done. I am a great believer in doing a route or part of a route then if things change you know where you stand.’

The forecasting challenge will always be central to the difficulties of winter service and the increasing amount of data on road temperatures is making the situation more complex. One attendee pointed out: ‘Historically you had a weather station and forecasts for that location. Over time you would learn of any biases in that station. Now we have lots of sources of information. So how do we bring all that data together to help decision-making?’

It was suggested that ‘saturating the network’ in cheap sensors connected to the Internet of Things was one way towards a more real-time understanding of road temperature. However, those around the table also described the dangers of data overload and how it was a ‘nightmare’ for local authorities to discover they had data that they did not act on. A danger created by big data is it potentially increases the number of borderline decisions, one attendee suggested. Do you need to grit a route if only 4% of it is falling below threshold levels?

An attendee pointed out that authorities ‘do need to look at how we can get a risk-based approach into decision-making’ and added that with route-based weather forecasting ‘you are effectively being told a pessimistic forecast because you are told the worst case scenario’. ‘We don’t want to be driven by minimum temperature, we want to be driven by hazards. Some of those hazards will be meteorological, some will come from other areas.’

However, the traditional model of forecasting does appear to be open to reforms.

‘If you take a decision at lunchtime and the action is at 3am there are clearly opportunities to rethink that decision. There is clearly an option of being more dynamic in that way. There is always a case for adding a reactive element.’

It was revealed that the National Winter Service Research Group will be establishing a working group on the issue of a risk-based approach to winter service.

It was also revealed that Highways England is going through a major shake-up of its approach to weather forecasting and winter service as well as developing a research project on residual salt, which could benefit the entire sector.

‘We are looking to integrate our contracts. We have 13 major contracts across our network and we are looking to pool all of those contracts into one super contract and make efficiencies in that way. We have already integrated five into our national contract and we have made significant savings with that. We have made it mandatory to do route-based instead of domain-based forecasting. That will give us the opportunity to hopefully think about selective spreading in the future. We are not quite there yet but that’s where we see us heading.’

Highways England has already introduced its integrated Severe Weather Information System that collates data from weather forecasting, the spreader fleet and the decision-making process itself. This platform was introduced in autumn last year but there are aspirations to keep developing the system and push it further.

The government-owned company must treat all of its network when necessary, but in terms of route optimisation it is looking to employ ‘a sub-set of routes in different weather conditions, alongside the standard set of routes’.

‘We can have route guidance to support drivers but automated gritting is some way off. There is an element of risk. In terms of switching gritting on and off and varying spread rates and widths, we know that capability is there. We are in development stage. We know that some authorities are implementing this and have talked about savings of 30% in salt just by more accurate spreading in the right places. We have the capability to do that but it won’t be a national scale roll-out. We would probably do some trials.’

The debate returned to the idea of the risk-based approach and there was some discussion over the nature of resilience. Local authorities have already developed key gritting networks, however these could become even more targeted. A question arose over whether links to amenities should be protected in the event of severe weather as well as key sites such as hospitals. One attendee said local authorities could not afford to ensure routes to supermarkets were open in the most extreme situations. However, it was forcefully argued by others that this was essential and a key method of ensuring residents are in a position to help themselves.

Another issue explicitly raised by the code of practice is how far an authority had to coordinate its winter service practice with neighbouring councils. One attendee suggested that authorities should do more to coordinate actions ‘outside of a crisis situation and on the regular stuff’.

It was pointed out that no authority wants to be ‘out of kilter’ with others in terms of its winter service plan as this increases its liability risk. However, one attendee pointed out there is an issue of where you draw the boundaries - if every authority wants to be in line with their neighbour it would ironically end up with the sector returning to a national standard.

It is clear that while authorities are being presented with a wide array of new options, a lack of cash and a fear of the risks involved in innovation present major barriers to taking up such options. One attendee explicitly said their authority was considering thermal mapping but wanted to see how others fared first. Highways England appears to be in the enviable position of having both the appetite and resources to try new things and could perhaps be the pace setter in winter service in the years to come.

Cold Comfort 2018, the 27th Annual Winter Maintenance Conference and Exhibition takes place at the Ricoh Arena, Coventry on 16 and 17 May 2018.

Register your interest today at and we will keep you informed with the Early Bird Discount offers and programme updates.


Adrian Tatum , TransportNetwork Events

Bryan Beitzel, Village of Buffalo Grove

Richard Stacey, Hertfordshire CC

David Batchelor, Highways England

Ross Bevan, Hertfordshire CC

Tony Bemrose, Meteo Group

Karin Harwood, Somerset CC

Danny Johns, Vaisala

Richard Hewitt, Highways England

Chris Cranston, Devon CC

Bernhard Dolinek, Mercedes Daimler

Peter Turland, Doncaster MBC

Ben Brown, Vaisala

Arjan Ruiterkamp, Aebi Schmidt

David Harvey, Aebi Schmidt UK

This article first appeared in the June 2017 issue of Highways magazine.

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