With the British government recently announcing plans for a trial of truck platooning, Jemma Dempsey investigated the practicalities of the system and the challenges of turning the idea into reality

At the beginning of April, three Volvo trucks pulled into a terminal in Rotterdam having completed a rather unusual journey from Gothernburg. On the initiative of the Dutch Presidency of the European Union, the EU Truck Platooning Challenge saw the three HGVs communicate wirelessly and drive closely behind one another in a close-grouped convoy ' a 'platoon'. And it was pronounced success.

Project manager Anders Kellstr�m said: 'We drove in a convoy for more than 1,500km on public roads and gained a lot of great experience, not just about the technology but also about the traffic environment. Everything went totally according to plan.'

The principle behind platooning is not a new one but it is only recently that the technology has been developed to turn the idea into reality. Its appeal is clear: when trucks drive closely behind one another fuel economy is improved because there is less drag. Figures show drag accounts for up to 25% of a truck's total fuel consumption, so the closer trucks drive to each other, the greater the fuel-saving potential. And using wireless technology, trucks can drive safely with just a one-second gap between them. By communicating with each other, they instantaneously match each other's actions, such as speed and braking.

'Essentially, this means that the reaction time for braking is reduced to zero which, in turn, improves safety and minimises the accordion effect associated with traffic congestion,' said Kellstr�m.

And now the British government is on board: keen to accelerate changes in the UK, it signalled in the Budget earlier this year that trials of truck platooning on the strategic road network would take place alongside trials of driverless cars and other efforts to introduce a more intelligent transport system.

The engineering and environmental consultancy Ricardo was commissioned by the government to carry out a feasibility study into the issues faced by legislators, haulage companies, drivers, trunk-road operators and other road users. The goal was to establish whether a road trial of an HGV platoon should be considered. The outcome was that it became clear that the only practical way to investigate platooning was in a real environment.

The Department of Transport said: 'New technology has the potential to bring major improvements to journeys and the UK is in a unique position to lead the way for the testing of connected and driverless vehicles. We are planning trials of HGV platoons and will be in a position to say more in due course.'

Although The Times suggested trials would take place on a quiet stretch of the M6 motorway in Cumbria in 2016, this has yet to be confirmed but it is clear the government is not alone in its drive to succeed. A recent survey by leasing firm Venson found nearly half of motorists supported truck platooning, especially if it could reduce CO2 emissions and make the roads safer.

However, not everyone is convinced. Motoring organisation the AA is sceptical. President Edmund King has questioned the feasibility of a lorry platooning scheme in the UK, saying: 'The problem with the UK motorway network is that we have more entrances and exits of our motorways than any other network in Europe or indeed the world. Therefore, it's very difficult to have a 10-lorry platoon because other vehicles need to get past it to enter or exit the road.'

This sentiment is echoed by Paul Watters, head of roads policy with the organisation. He believes the problem with our motorways is that they simply haven't kept up with the growing demand for space and, as a consequence, platooning would be tricky to integrate.

'If trucks operate in a new way that requires special systems to interact with the other traffic on the motorway it could reduce capacity,' he said.

'For example if all the trucks had to move to the offside to free up the entry and exit slips, it would reduce capacity. And they'd then have to go back to their initial lane at the appropriate time and that manoeuvre would cause further congestion. Ideally, there should be a dedicated lane but there should be dedicated entry and exit points too.'

Safety is a concern too. Watters says the blocking of road signs by a convoy of trucks is very significant.

'It certainly will make it difficult to see signs on the nearside,' he said.

'And, interestingly, the smart motorways that are having the hard shoulder taken away are now becoming reliant on signs on the nearside. So if you've got a platoon of high sided vehicles they will obscure the view to the left so drivers might miss important messages that the smart motorways rely on for safety.'

All of which is why Ricardo says the only way to test the practical nature of platooning is to have on-road trials. A spokesman said: 'The trial could investigate the effects of platoon length. Platoons as long as 10 trucks seem unlikely in the near future but the fuel savings are still very good for two-truck platoons. For longer platoons, it is possible that a platooning system could be designed so that the platoon temporarily splits into smaller units to enable easier access at junctions.'

Ricardo's belief that this can work is echoed by Giles Perkins, the technical director in intelligent transport for Mouchel Consulting. How does he reconcile the concerns of the AA and others about using this technology alongside other transport?

Perkins said: 'Imagine the driver of the third truck made a request to say he wanted to leave the platoon. He'd get permission to take charge of the vehicles behind him. Then the fourth driver would take control of the platoon behind him so the third driver could move out. And then the two platoons would come back together.'

And what of the obvious concern about obscuring road signs? Perkins said: 'This is where other technologies and advances that are being considered will come into play. There's no technical reason why the traditional display of information on a sign at the side of the road can't be provided in-vehicle. When you consider most new vehicles now come equipped with some form of flat screen, within a few years you'll start to see more and more information provided to drivers in their own environment ' in-cab if you like ' so you might be able to mitigate against some of those problems.'

In 2012, a major EU study, managed by Ricardo, demonstrated fuel economy benefits of 8% for the lead truck and 16% for the trucks following it when platooning at 90kph (56mph) and with vehicles 5m apart. It should be noted, of course, that actual fuel savings for hauliers would depend on how much of their journey was spent platooning. Sarte (Safe Road Trains for the Environment) also looked into costs. It estimated the initial investment required for equipment and lead-driver-training would be £2,750 (�3,500). Additional annual maintenance and platooning service costs were estimated at £235 (�300). As a result, over a typical ten-year lifetime of a truck, savings would need to be in the region of £510 (�650) each year to commercially justify the system.

But the Ricardo spokesman said: 'In many respects, the technical and engineering challenge of creating a safe system for platooning is more straight forward than resolving issues of the regulatory frameworks and achieving public acceptability.'

In other words, the rules surrounding safe driving distances between trucks varies across the EU so law changes would be needed.

And it's not only the AA that needs convincing. The Road Haulage Association, which is working with the Department of Transport to support the trials in the UK, believes the case for road safety has to be proven first. Director of policy Jack Semple said while there are obvious and significant benefits, there's well-founded scepticism in the industry about how it would work in reality on a busy road filled with cars.

But while the benefits shouldn't be overlooked, it does pose a challenge for fleet managers in how it affects existing distribution models, in particular having absolute flexibility over where individual vehicles go. Giles Perkins said: 'The flip side to that is that it might allow fleet managers to look at efficiency savings, fuel savings and the health and well-being of staff ' particularly if drivers aren't all facing the burden of driving a vehicle all of the time.'

The Intelligent Mobility Fund has £100 million of government money to invest in a range of transport innovations. But convincing the general public that a system like platooning can work alongside normal vehicles might prove more difficult. Comments on forums and social media have so far been at best mixed. Clearly, the challenge ahead remains significant.