Britpave: The British In-Situ Concrete Paving Association

Research finds concrete roads save fuel costs

New research has confirmed that driving on concrete roads can significantly reduce the amount of fuel used.

The research, carried out by the Massachusetts Institute of Technology Concrete Sustainability Hub, is the first to use mathematical modelling rather than field trials. It found that the decreased deflection of stiffer concrete pavements could reduce fuel consumption by up to 3 percent. The Sustainability Hub calculates that in the US more than $15 billion in annual fuel costs could be saved. Deflection occurs when a vehicle’s tyres roll along a pavement and has the effect of making the vehicle drive continuously up a slight slope. This increases fuel usage. The effect is similar to the energy and effort required when walking on beach sand.

The research produced a rigorous mathematical model relating fuel consumption with mathematically predicted pavement deflection. It found that stiffer concrete pavements reduce this deflection. The study has been welcomed by the infrastructure group Britpave as further proof of the whole life cost and life cycle sustainability benefits of concrete roads.

The findings of the Sustainability Hub underline those of a recent report, ‘Concrete Pavements Contribute to Decarbonising of Transport’, from Eupave, the European Concrete Pavement Association. This pulled together the results of a number of independent international research studies which compared the fuel consumption of heavy good vehicles using concrete and asphalt road surfaces and examined the impact of a number of factors, particularly that of rolling resistance which has a direct influence on tyre-pavement interaction and, therefore, fuel consumption and CO2 emissions.

The studies found that the stiff and rigid concrete road pavements analysed exhibitied significantly reduced fuel consumption by heavy goods vehicles when compared with the flexible deflection prone asphalt pavements. The Eupave research reported savings of up to 6.7%. This not only offers significant financial savings but given that road haulage in Europe produces some 40% percent of transport CO2 emissions there is a significant environmental benefit too.

Eupave examined research carried out by the National Research Council in Canada, the Transport Research Laboratory in the UK, the Swedish National Road and Transport Institute and Lund University and the Nippon Expressway Institute in Japan. Additional research carried out by the Massachusetts Institute of Technology determined that asphalt pavements would need to be 25% to 60% thicker to provide the same level of stiffness and consequent fuel savings as concrete pavements.
Collating the research findings, Eupave concluded that a 100km concrete road with a daily traffic of up to 15,000 heavy goods vehicles would over a 30 year period save up to 400,000 tonnes of CO2.

Commenting on the research, John Donegan, Chairman the Britpave Roads Task Group, said: “International research has repeatedly demonstrated that concrete pavements out-perform asphalt pavements in relation to fuel savings. Reducing fuel consumption provides both direct cost and sustainability benefits.”