Why we like to drive in the middle of the road

Carefully does it: one of the Leeds guinea pigs sticks to the middle of the road. Photograph courtesy of the Journal of Experimental Psychology Human Perception and Performance. Advance online publication [doi: 10.1037/a0026568]) reprinted with permission from the American Psychological Association.: Leeds University Here is a New Year sign of progress on the vexed issue of 'middle lane hogging' on roads which forms such a treasured part of the UK's national debate. It comes not from the taproom at the Coach and Horses but the Institute of Psychological Science at the university of Leeds. Researchers there have established that older drivers have a 'built-in safety mechanism' which inclines them to drive in the middle of the road to avoid manoeuvres which could test their gradually slowing reactions. I am not (quite) old enough to be a useful guinea pig in such experiments, but other silvery citizens of Leeds joined in the project with gusto. They were given a touch-screen laptop and asked to trace wiggly lines of varying widths - slowly, quickly and at their own preferred pace. The next stage was steering along 'virtual' winding roads in a driving simulator, with a complimentary tour of the labs to conclude the process. Kathleen Dawson, who is 81, says that she felt: that at some points I was being forced to drive too quickly. However, I was happy to take part because I realised the importance of this type of research. It was explained to me that in learning how healthy people 'work' it helps scientists and doctors to provide new methods and means for treating people with movement problems. Her junior Lillian Watson, 75, says: I enjoyed being shown around the Labs and I felt privileged to be asked to take part in research. The findings also interest me because in hindsight - when I was in the simulator I did actively try to stay in the middle of the path for fear of going outside of the lines. The faster it got, the more I had to concentrate on doing that! The pair were typical of their age group in adopting a 'middle-of-the-road' strategy as a deliberate way of making allowances for their reduced drivings skill, of which they were aware. In the tracing exercise, older volunteers remained well within the wiggly lines indicating twisting and turning lanes, and stayed in the middle of the road on the simulator. A parallel group of drivers aged 18-40 had a greater tendency to cut corners and use the road's full availability to manoeuvre. The difference only reduced when all the volunteers were given narrower lanes on the laptop or asked to drive faster on the simulator. The results are published in the latest issue of the Journal of Experimental Psychology: Human Perception and Performance. (payment required) The purpose of the work is partly to tackle the road-hogging issue, which may have to await the Day of Judgment, than to analyse behaviour in a way which may suggest new ways of helping patients to recover lost motor skills, for example, after a stroke. The experiment's volunteers did not get on to 'virtual' motorways during the research; their 'middle of the road' approach was confined to the lanes set out for them on the laptops and the simulator. But their 'compensation strategy' of avoiding too many changes in direction would appear to chime with those who defend middle-lane driving on motorways as preferable to what they regard as 'dodging in and out.' Dr Richard Wilkie who supervised the project, says that the use of wing mirrors and judging distances when changing motorway lanes are the sort of manoeuvres which older drivers appear to use cautiously because of reduced skill. Postgraduate researcher Rachel Raw, the lead author of the study which was also carried out by Georgios Kountouriotis, Prof Mark Mon-Williams, and Dr Richard Wilkie, says: Our results suggest that a compensation strategy is a general phenomenon and not just tied to driving. It seems older people naturally adjust their movements to compensate for their reduced level of skill But this compensation can only take you so far, and when conditions are difficult, perhaps because of snow or hail, or when driving at night time on poorly lit roads, older adults can struggle. Dr Wilkie, who supervised the tests, says: It is important to establish what strategies are adopted by older drivers in order to ensure their safety – as well as the safety of other road users. Understanding how older people learn to adapt to a diminished level of skill has implications for our approach to rehabilitating patients with reduced movement. Road safety is particularly relevant to older people because, as the paper notes, they are more likely to be involved in fatal accidents than younger ones, in spite of all the bar-talk about young speeders et al. The report notes: In the real world, a reduced consistency in road position makes it more difficult for the driver behind to safely complete manoeuvres that rely on the stability of the leading vehicle's road position (e.g., overtaking and merging). Likewise, driving too slowly increases the variance in the speed of vehicles traveling together, which increases the risk of accidents (Garber & Gadirau, 1988). Slow driving can frustrate other drivers, leading to risky overtaking manoeuvres (McGwin & Brown, 1999). It seems, therefore, that older drivers' compensatory strategies may not always be sufficient to ensure road safety.