Active safety systems could save lives

Many car owners only look at crashworthiness scores when selecting a car and seldom look to see what life saving active safety features are available. What do phrases like active and passive safety really mean – how do they work and cut accidents, particular in winter driving conditions?

Active safety aims at preventing accidents happening in the first place. Cars are equipped with a number of systems to help the driver control the car BEFORE an accident might occur.

Passive safety describes the safety systems which are built into cars to protect the driver, the occupants and other vulnerable road users AFTER the accident has happened.

Carmakers have made enormous strides in recent years on passive safety in no small part due to the evaluation of the safety levels awarded to every new car by Euro NCAP. More and more new cars today have won the top "five stars" accolade from Euro NCAP.

Development on active safety, however, has really moved forward in recent years with driver knowledge of how the various active safety systems work often lagging behind the in the provision of such equipment as either standard or as an option on the car.

RoadSafe’s Director, Adrian Walsh says, 'We’re surprised how little most drivers know about the active safety systems on their cars. Developments in active safety offer real life saving advantages to drivers, particular in the wet, winter months. With the facts before them, we believe drivers would unhesitatingly demand these systems in their cars as they offer substantial benefits in reducing accidents on our roads.'

Current active safety systems

All new cars in the UK are now fitted with ABS – Antilock Braking System. Invented over 30 years ago, ABS stops the car wheels from locking up during braking by controlling the brake pressure. A sensor on each wheel measures the wheel’s speed with the speed of the car (known as the "slip") The sensor regulates the pressure at each wheel to prevent a lock-up.

The result is that a car with ABS will stop more quickly and will be more stable on all surfaces. ABS comes into its own when the driver has to brake hard to avoid, for example an animal in the road or if a driver has to brake and steer round an unexpected obstacle without skidding.

The next main development is TCS (Traction Control System), which builds on ABS by adding extra valves to the system’s hydraulics. Preventing wheels from spinning, it often interacts in situations such as braking with near-side and off-side wheels on different surfaces, hard acceleration and driving in slippery conditions.

During research Mercedes-Benz engineers discovered that drivers often do not step on the brake pedal hard enough and developed Brake Assist as a solution. The brake pedal engaged at a specific speed is indicative of an emergency situation and the system automatically generates maximum brake boosting power. While there is no danger of the wheels locking, the advantage is clearly the significantly reduced braking distance.

In 1995, the next milestone in active safety was set with the introduction of Stability Control Systems, mostly known as ESP – Electronic Stability Program. Developed by Bosch in conjunction with Mercedes-Benz, the system - comprising ABS and TCS - detects vehicle skidding and actively counteracts it. Identifying dangerous situations it reacts instantly without any action on part of the drive, reducing engine power to restore vehicle stability, and if required, braking individual wheels.

In a recent announcement Professor Claes Tingvall, chairman of Euro NCAP said, "Euro NCAP’s role is to alert the consumer to cars which offer the greatest protection in an accident. However, the safest car on the road is the one which does not get involved in accidents. Driving carefully and attentively is perhaps the best way to reduce the chances of being in a crash but technology can play an important role, too. That is why we are extending our advice to the motorist to cover developments in technology, such as Stability Control, which will help protect them and their passengers"

A recent study by Daimler Chrysler showed that ESP reduced collisions by 42 per cent and The Swedish National Road Administration reported in 2002 that ESP had reduced accidents on the country’s roads by 22 per cent in dry conditions and by some 33 per cent in the wet.

Adrian Walsh summed it up, "If this was applied to British roads it could save some thousand deaths and serious injuries a year"

However, according to Bosch, installation rate figures in the UK are among the lowest levels in Europe with only 29 per cent of new cars fitted with ESP compared to 55 per cent in Germany and a European average figure of 37 per cent.