Health: Out on the road, driving everyone crazy: Stanley Slaughter learns how to identify the type of motorist most likely to turn into a menace because of frustration and aggression

IT IS a familiar scene: a driver stuck at a busy junction, waiting for a gap in the endless stream of traffic. The frustration mounts. A recent report on driving attitudes suggests that for some, this frustration is simply too much. A few just pull out, risking not only the lives of the people in the oncoming car but also their own and those of their passengers.

Just what is it that makes some people drive in this crazy, possibly self-destructive way?

Dr Derek Packham of Newcastle University's psychology department, who co-wrote Risk and Safety on the Roads: Perceptions and Attitudes, published by the AA Foundation for Road Safety Research, says that for these people, driving is like the jungle: only the fittest survive.

He and his co-author, David Silcock of the university's transport operations research group, noted two types of people who viewed driving in terms of the need to dominate. The first were self-oriented and compulsively kicked against the constraints of a social order; second were the 'pretty unconcerned who really didn't know and didn't much care'. For the latter group, the too-strict rules of the road were a challenge, and a busy traffic flow that excluded them was like a red rag to a bull.

Most such drivers were young males, but Dr Packham, in the survey of 200 drivers in the North-east, also found that middle-aged, confident men were not entirely guiltless and that there were reports of women at the wheel acting in an aggressive manner.

The first thing these drivers noticed when they got on the road was, in Dr Packham's worrying phrase, the 'nature of the competition'. Others factors, such as the number of pedestrians, traffic lights, visibility and road layout were all minor compared with the competing traffic flow - that is, who was likely to get in their way.

One disturbing finding was that drivers behaved no differently when passing through pedestrian-free areas than when outside busy Newcastle Central Station. If the lights were with them and they had a clear run, they would drive just as fast.

The AA has drawn up a pen picture of the young male likely to drive in this single-mindedly aggressive way. He is, first of all, someone who enjoys taking risks and believes that by doing so he is impressing his circle of, mainly male, friends. He may also pursue sports that involve risks, such as hang-gliding or off- road mountain biking.

For him, good driving is equated with demonstrating control of the car by abrupt stopping or sharp cornering and successfully carrying out risky manoeuvres, such as squeezing past cars on a crowded road.

He also sees his vehicle as a passport to freedom and power, which on packed roads it clearly is not. For him, driving is almost an obsession. He probably took his test within months of his 17th birthday, enjoys tinkering with the vehicle and spends hours talking to his mates about cars and driving.

His mood will also affect his driving. If he is depressed or fed up, he will drive more aggressively. The problem is that it is other drivers with their occupation of 'his' road that is likely to plunge him into such a mood.

Dr Packham believes that his two aggressive groups are on the fringe of society, along with joyriders 'who are in it for the status and power that could not otherwise obtain' at the very edge.

But Dr Steve Stradling of Manchester University, who also has researched aggressive drivers, believes they may be more numerous than we like to think. Certainly, increasing instances of drivers blithely sailing through red lights in London adds force to his point.

He puts forward seven reasons why drivers may behave in an over-aggressive and sometimes dangerous way.

They may simply be late for an apppointment and so feel under pressure. They might feel pressed by other drivers behind them, perhaps waiting to come out of the same junction or make the same right turn. They see others take a chance and decide that they will follow suit.

They do it for the thrill of it, or to gain one of life's little victories that they can tell their wives, office colleagues or pub cronies about for the next few weeks.

They drive that way because they always have, just like their parents or peers have shown them.

They are in a bad mood after a row or a perceived snub - or, more likely, have put themselves into a bad temper.

They are under stress, an underlying theme of some of his other reasons. Dr Stradling said driving was an 'unnatural act', adding: 'I suspect it is more stressful than many people think, and when people are under stress you get extreme reactions and bad decisions. That is one reason why they are likely to be more dangerous.

'They are tensed up because they do not like what they are doing because of the traffic. It is unnatural because they are on show. Their performance is being appraised and assessed by other drivers.

'They are performing in a semi-public arena and having semi-social interaction with other people, just like in a supermarket, but there is no face-to-face contact. That puts them on edge - and then add in the frustration of being caught in a gridlock.'

Dr Stradling rejects as an 'urban myth for which there is no evidence' the idea that people change their personality or that they show their 'true' colours when they climb behind the wheel of a car. He adds, however, that no real research has been done into how aggressive drivers behave away from their cars.

The Institute of Criminology at Cambridge, which has done research into predicting criminal behaviour, has found that excess speed and generally bad driving were indicators. But such cases made up only a small proportion, which suggested they were people who had total disregard for the law, be they inside or outside a car, not the apparently larger numbers of which Dr Stradling was talking.

His next project is on dominance, which he suspects may show that some people just have to act in that way - the same people who, according to the old expression, think they own the road as well as the car, and for whom ceding space to another driver is too much for their pride. They cannot ever give way.