In-road sensors weigh lorries in motion

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A project taking place in Norway aims to deter hauliers from overloading their vehicles by developing a system that checks and weighs HGVs whilst they are in motion.

Advanced sensors installed in the road surface, combined with number plate recognition systems, will enable the detection of far more incorrectly loaded trailers.

Scandinavian research centre SINTEF is heading NonStop, a Norwegian Public Roads Administration-commissioned project, with partners including the Norwegian Hauliers’ Association and the Oslo firm Ciber.

The aim of the project, now half-way to completion, is to make commercial road haulage more efficient by ensuring that only incorrectly loaded vehicles are stopped for inspection.

The technology used involves a Weigh-in-Motion (WIM) sensor system which measures the weight of the vehicle using a cable sunk into the road surface.

The sensor in the cable utilises PIEZO technology; the cable generates an electrical voltage when subjected to pressure, and in this way can record the weight of a vehicle passing over it. The information is then sent to a computer.

‘This technology is well established’, said SINTEF’s Terje Moen in a statement. ‘However, it must be adapted and assembled to ensure optimal application and function.’

The project will employ automatic number plate recognition (ANPR) technology to read vehicle number plates. The number plate can then be searched for in public registers where specifications such as a vehicle’s permitted load will be entered.

Measured weight, data from public registers, the provisions of the statutory regulations governing technical requirements for motor vehicles, and the day-to-day practical expertise of the NPRA inspectors are then built into a decision support system that aims to help inspectors select candidates for checking.

‘It will also be possible to link the system to data transmitted from the vehicle itself,’ said Moen. ‘A modern vehicle is installed with a ‘brain’ which can measure how far it has travelled, its weight and the duration of stops it has taken along a given section of route. It is this aspect which makes the project unique in a global context.’

As well as improving road safety the searchers believe that the new system will also bring considerable environmental benefits.

‘A vehicle…which is stopped for no good reason wastes a lot of fuel accelerating to regain its normal speed’, said Moen,

The project is financed by the Research Council of Norway via the SMARTRANS programme. A demonstrator will be ready for testing on vehicles this summer, and the system will be rolled out in full in the summer of 2014.