Keep on trucking

Almost everything we consume arrives on a truck, even if its road trip represents just part of its overall journey. Lorries bring us the things that we need – but, as substantial users of diesel, they do so at significant cost. That cost is not just financial; it’s also social and environmental.

A new initiative – the Centre for Sustainable Road Freight – was launched in December 2012 to look at the ‘big picture’ of the movement of freight by road in the UK and to explore ways of making the sector more economically, socially and environmentally sustainable. The reduction of carbon dioxide and other greenhouse gas emissions, which contribute to global warming, is a key objective of the programme, in tune with the government’s targets of 34% reduction (compared with 1990 levels) by the year 2020, and 80% reduction by 2050.

The Centre, which has £5.8 million funding for the first five years, is a partnership between the University of Cambridge’s Department of Engineering and Heriot-Watt University’s Logistics Research Centre. It is headed by Cambridge’s Professor David Cebon, an engineer with expertise in the dynamics of heavy vehicles, who leads a team of ten academics from the two institutions: “The Centre draws on the strengths of both institutions – Cambridge’s skill set in engineering and Heriot-Watt’s capabilities in logistics. It brings together experts from a wide range of fields, from the aerodynamics of vehicles through to logistical operations and driver behaviour.”

A vital feature of the Centre is its close links with the freight industry. Of the initial funding, £4.4 million will come from the Engineering and Physical Sciences Research Council and £1.4 million from a new industrial consortium. The consortium will comprise freight operators such as DHL, John Lewis Partnership, Tesco and Wincanton, as well as vehicle industry partners including Firestone, Goodyear, Haldex and Volvo. These companies will help to set the research agenda and set the pace in the adoption of results. With fuel representing, on average, 45% of operating costs, and with aggressive emission-reduction targets set by government, the road freight industry has substantial incentives to minimise its use of diesel.

The programme will look at the most influential factors that govern fuel usage by the road freight industry to develop a road map for the industry and help it meet emissions reduction targets. The key is to have a sequence of practical interventions, both logistical and engineering, which are socially acceptable and economically attractive, and which drive down emissions. “It is no use having an ambitious end point if there is no practical way to get there,” said Cebon. “Our aim is to focus on the big-picture issues and make sure that the most important factors get the right amount of industrial and political attention, at the right time.”

To illustrate this point, Cebon explained how an improvement in vehicle aerodynamics would reduce fuel consumption for motorway operations – but that advance in performance may be small when matched against other factors such as traffic congestion, which is heavy on fuel consumption. He said: “A viable reduction in fuel consumption due to improved vehicle aerodynamics is 5%. If you set this against the extra fuel used in one unscheduled vehicle stop, it would take about 45 km of continuous driving by the improved vehicle to break even. Although improved aerodynamics does make a difference, traffic flow is hugely influential, meaning that improved road systems, better route planning and delivery time scheduling can make a big contribution to reducing fuel consumption.”

The Centre is guided by the ‘triple bottom line’ approach to sustainability: planet, people and profit. In devising workable solutions, the second and third of these are as important as the first. The public might complain about emissions and noise, and lobby to keep trucks out of residential areas, but lorries are the lifeblood of the country’s economy. Without freight transportation by road, the economy would grind to a halt within four or five days. All along the supply chain, companies rely on just-in-time delivery systems working 24 hours a day, seven days a week, on narrow profit margins. According to the latest figures, some 400,000 lorries and 290,000 drivers deliver around 3.9 million tonnes of freight on a daily basis.

One of the aspects of freight transport that offers most potential for reducing fuel costs, and thereby emissions, is to maximise loads. When a vehicle delivers its freight and returns empty, the energy used for the return trip serves no useful freight purpose and the fuel consumption per freight task is increased by 70%. The solution to this problem lies in improved logistics management and collaboration between different operators. Similarly, when freight is taken off a large articulated truck and put on two smaller trucks, 40% more fuel is used. In this case, there is an opportunity for the development of large vehicles that are more manoeuvrable in narrow streets and safer for vulnerable road users such as pedestrians and cyclists.

Modern trucks are designed to be aerodynamic with smooth shapes that offer least wind resistance and skirts to streamline air flow. An area of aerodynamics that has thus far been largely neglected is the underside of trucks. This aspect of truck design is being investigated by a team led by Cambridge’s Professor Holger Babinsky, who has worked extensively on the aerodynamics of Formula 1 cars.

Measuring the flow between the underside of a truck and the ground it is passing over presents a particular challenge because of the difficulties in running realistic wind-tunnel tests. Using a model truck, researchers have developed a method of scaling up some of the parameters by towing the model through water in a glass tank. “We think that the underside of a truck contributes as much as 30% of total drag and that by redesigning the underside we can reduce that figure by 10 to 20%,” said Babinsky.

Over the next five years the Centre’s research programme will generate a series of software and hardware systems. Software systems will include logistical management and vehicle routing tools, software to advise operators on energy efficiency options, and databases of logistical information. These will help operators with the complex task of planning deliveries to meet the needs of suppliers and consumers while minimising environmental and social impact. Hardware systems will include improved aerodynamic systems, low rolling-resistance tyres, lightweight trailer designs and regenerative braking technology whereby the energy expended in braking is captured and reused.

“What’s exciting about the Centre is the fact that it brings together so many leaders in their fields,” added Cebon. “By working together and focusing on both the logistical issues and vehicle engineering we can devise solutions that will make a major contribution to sustainability in the road freight industry.”