With 15 per cent of deaths on Britain’s roads involving drivers who were over the legal limit, Saab has created a new concept to combat the problem.

The Swedish manufacturer has created a miniature alcohol-sensing device which will encourage drivers in observing drink-driving laws.

The Saab Alcokey concept includes a small mouthpiece in the car’s key fob. A transponder communicates with the car’s electronic control unit, immobilising the engine if a driver’s breath sample is found to contain alcohol above the permitted level.

The device could be made available as an accessory through Saab dealers and is currently under evaluation.  In commercial production the Alcokey concept would cost about 250 Euros (¬£165) , or a tenth of the cost of a fixed system installed inside the car.

The Alcokey concept is an adaptation of existing anti-theft technology. When the driver presses the ‘doors open’ button on the car’s remote control fob, the alcohol sensor is also switched on.

The driver then blows into a small mouthpiece at the end of the fob to provide a breath sample which passes down a small internal tube containing a semi-conductor sensor the size of a pin-head. The sample is analysed and a small green or red light on the fob is illuminated.

If the green light is shown, the key will transmit an ‘all clear’ signal to the car’s ECU. This is in addition to the usual signal the key always transmits to switch off the engine immobiliser.

But if a red light is shown, the ‘all clear’ signal will not be sent and the engine will remain immobilised. The software instructing the engine immobiliser can be adjusted according to the alcohol limits in operation where the car is registered.

The current prototype Alcokey is a separate unit, about 4in long and 1.5in wide (10cm by 4cm) and is in addition to the conventional Saab combined key and remote control. In production, further miniaturisation would allow both to be contained in a single, pocket-sized unit.

Companies operating large car fleets, with employees driving a great deal on business, are anxious to demonstrate their social responsibility by having an alcohol-monitoring device fitted as standard. And in some countries, it may even become mandatory to fit them.

Saab Automobile’s President and CEO, Peter Augustsson, said: “Alcohol consumption is increasing in many countries and this often leads to a greater incidence of drunk-driving,” he said. “As a car manufacturer, Saab is keen to do what it can to help prevent such behaviour.”

The Swedish National Road Administration is supporting Saab’s work and its director, Ingemar Skog√∂, says he is pleased to see Saab pioneering such a practical aid to safe driving. “We all have a duty to discourage drunk-driving and this is a valuable initiative that other car companies should consider following,” he said.