29 September 2021

To help the haulage sector meet climate targets the UK's motorways are being electrified. How do you efficiently wire up a complex road network while keeping on trucking?
An electric HGV heads out on the highway

With transport contributing around a quarter of UK greenhouse gas emissions, the race is on to decarbonise vehicles to help hit the country’s net-zero target by 2050.

Freight transport is a particular challenge. In July 2021 the UK Government said it would fit motorways with overhead electric wires to power e-trucks and charge them on the go, like electric train or tram lines, as part of a plan to ban the sale of diesel-powered HGVs by 2040.

These so-called Electric Road Systems, or catenary systems, had a mixed response. The Road Haulage Association raised concerns about the costs (the UK plan is estimated at around £17 billion) and described it as "blue skies aspiration ahead of real-life reality".

However, the Government announcement drew on a 2020 report by the Centre for Sustainable Road Freight, which said catenary systems were "technically viable, economically attractive, and could be achieved by the late 2030s".

One researcher looking to shine more light on some of the challenges around installing Electric Road Systems at scale in the UK is Alejandro Gutierrez-Alcoba of the University of Edinburgh Business School. He is a Marie Curie Fellow whose research work is supported by the European Union Horizon 2020 fund, the Data-Driven Innovation initiative in Edinburgh and Costain, and other industry partners.

Electric Lorryland

"Freight transportation must be transformed to hit net-zero targets," he says. "Technologies such as Electric Vehicles (EVs), combined with the production of electricity using renewable energy, can help to move towards a low carbon economy. However, and especially for HGVs required for freight transport, EVs have limitations — volume and weight of electric batteries, availability of certain raw materials needed to manufacture them, and tensions when trying to replace internal combustion engine vehicles for electric ones globally. That is a big challenge."

Another hurdle is the time needed to roll out large-scale systems. The fragility of the supply chain, and HGVs place within it, has been underscored in 2021, with a driver shortage leading to empty supermarket shelves. How then can the investment required to meet emissions reductions targets be managed, without undermining the ongoing activity of the logistics sector and ensuring the network can be used by other vehicles during the transition period?

Then there is the question of coverage. Even after Phase 3 of the plans announced by the UK Government, just two-thirds of the distance covered by HGVs across the UK would be on the catenary network.

Phase 1 of the system does not reach Scotland, but Phase 2 extends north of the border on the M74 and A1, and also includes the M8 and M9. Phase 3 reaches further north, including the A9 and A90, and into the south-west on the A77 and A75, as well as other central areas. Phase 1 could start as early as 2025, but each phase is expected to take 2 to 3 years, with the whole project potentially running into the late 2030s.

The Road Best Taken

When considering how best to roll the scheme out, Gutierrez-Alcoba is grappling with whether catenary systems should be installed on roads experiencing the highest traffic flows or whether it is best to maximise the length that can be travelled on electricity, either provided by the catenary systems or vehicle batteries. For freight operators, this aspect is critical when considering adoption of the new technology. Favouring the busiest roads only might not lead to the desired effect, to minimise global fuel usage and carbon emissions.

"One advantage of the catenary system is that vehicles can attach and detach from the system, and don't need to stop," says Gutierrez-Alcoba. "So you could put stretches of road with catenary and non-catenary sections; rather than having 100 miles all catenary, you might have 25 miles with and 25 miles without, then the same again. The vehicles are charging on the catenary section and using a battery for the non-catenary sections. If you do that, you could cover more of the road network with the same budget."

Route planning under a new electric road system network is at the heart of the research.

"You are not going to choose the road yourself," says Roberto Rossi, one of Gutierrez-Alcoba’s supervisors for the three-year research project. "That is not going to be possible in this system if you have a partially electrified road network where you need to go through a certain route to get from A to B. You need a planner, a tool that tells you where you have to go through so you can recharge yourself dynamically."

Data at the Wheel

Gutierrez-Alcoba’s insights will be data-driven, with major partners providing information. Highways England will give him access to data of hourly HGV traffic density on major roads. Costain, an infrastructure company, and other logistic partners will provide data of vehicles and their route operations.

"We will develop mathematical programming models allowing us to calculate optimal routing decisions on catenary road networks and to design roll-out plans to consider economical, physical and managerial factors involved in the deployment of the technology," he says. "We will also study the impact of uncertainty."

This includes an HGV’s load and the impact on the energy it uses. "We know that the weight of the vehicle with a cargo is one of the main factors in energy use," he says. "It is important to know how much a vehicle has to load or to deliver, and the impact on the weight.

"Right now, a truck driver doesn't have this consideration. The truck is full or empty, it doesn’t really matter — they just deliver according to a certain schedule. When companies like DHL or DPD start using electric vehicles, that consideration will be massive. Leaving off the biggest item first is the most important thing, and we don't think in that way now."

Electric Avenues

The researcher’s findings will present a case study of the UK road network, while data gathered for the project and relevant algorithms will have the potential for further research and useful tools.

Belen Martin-Barragan, his second supervisor, stresses that the outcomes have to be practical. "Optimization models are important in making decisions on what roads should be electrified first, so people believe in the system, and the final result is useful for society," she says. "Haulage companies are not going to go onto those electrified roads, and support investment if they are put on a road they never use, so the whole project may fail. That is why we need a plan on what roads need to be electrified first."

Gutierrez-Alcoba says introducing Electric Road Systems on major roads could happen in parallel with smaller and lighter batteries being used during the 'last mile' to a final destination, or on interchanges between sections of ERS roads.

Tim Embley, Group Research and Innovation Director at project partner Costain, says: "This is a strategic bit of research that will play a fundamental part in the modelling of the future route rollout over the next 30 years. The catenary system can unlock other opportunities in the future road network, so I think this research will be part of a transformational journey that the industry goes on, in terms of decarbonizing the strategic road network. I think it is a very important piece of the jigsaw.

"The UK has got some big, stringent targets on the decarbonisation of the road network so you will potentially have government incentives. Hauliers are looking with interest because it will drive greater efficiency and profit margins — and if it gets going in the UK, it will be more competitive for them."


Alejandro Gutierrez-Alcoba is a Train@Ed Research Fellow at the University of Edinburgh Business School.


A version of this article was originally published on ed.ac.uk.