Case Studies - Highways and Traffic

We have successfully used fibre optics to weigh moving vehicles - paving the way for a 'smart' highway infrastructure to ease traffic congestion.

Signals were multiplexed together onto a single fibre and interrogated over a distance of 20km. With a pair of sensors in each of two lanes QinetiQ determined vehicle direction, speed, axle weights, and axle separation for vehicles as different as a bicycle and a fully laden five-axle lorry.

QinetiQ has developed this traffic detection technology to help create a 'smart' highway infrastructure to ease traffic congestion.

QinetiQ sensors have a simple all fibre design, and can be easily implanted in the road surface. What's more, up to 100 individual sensors can be embedded and monitored through a single optical fibre over distances of up to around 50km. Indeed the sensors can readily be linked into existing fibre optic communication system cables that run along many major highway networks. This technology permits dense coverage, with sensors every 100 metres or so over a wide area without the need for costly roadside electronics. Something not easily achieved with current technology.

As well as identifying the type of vehicle we can also determine vehicle direction, vehicle speed and axle weights. This is a significant enhancement on traditional loop based highway monitoring and of great benefit to network planners, law enforcement agencies and maintainers.