The psychology behind how pedestrians, cyclists, and cars interact

A great discussion on the psychology behind how pedestrians, cyclists, and cars interact.

… the lack of understanding of the cyclist outgroup seems to produce measurable changes in other road users’ behaviour. A few years ago I did a study which showed that changing the appearance of a cyclist led to notable changes in how much space drivers left when passing the bicycle. The specific changes seen make sense given the small body of research on non-cyclists’ stereotypes of cyclists. The two extant studies – the Lynn Basford et al. one, and research by Birgitta Gatersleben and Hebba Haddad, in 2010 – both found that non-cyclists view bicycle helmets as an indicator of an experienced rider, and in my data we saw riskier behaviour from drivers when they passed a cyclist who was wearing a helmet, which fits the idea they saw the rider as more capable.

The positive lesson from this, I feel, is that drivers do adjust their behaviour to the perceived needs of the non-drivers they are interacting with. The problem is that they do not always understand how to read these other people and judge their needs.

What is the psychology behind most accidents involving bikes?

If you look at taxonomies of car–bicycle collisions – or, indeed, car–motorcycle collisions, which tend to be very similar – you see that the majority of collisions happen in just a few circumstances.

One of the key issues is where the rider is going straight along a main road and are hit by a driver turning right (in the UK), either into a side street or out of one. There’s actually a (very) small psychological literature on this, particularly the ‘looked-but-failed-to-see phenomenon’, which is where the right-turning driver looks at the rider but does not consciously become aware of the hazard. Unfortunately, this literature is so small it doesn’t provide very hard answers, but it’s likely the problem is drivers’ expectations, making it a top-down processing problem. The hypothesis is that drivers don’t expect to encounter cyclists at junctions and so their visual search patterns go to the parts of the road where cars and trucks are to be found, skipping the parts of the road where cyclists (and, to an extent, motorcyclists) are found. The way totest this is incredibly simple: behavioural analysis of drivers in, say, Cambridge or York (where one would expect cyclists at each junction) and Basingstoke (where one would not). We expect to see different visual search patterns – and fewer conflicts with cyclists – where cyclists are more prevalent.

Of course, there are also relatively low-level visual processes at work in car–bicycle collisions. David Shinar in Israel has recently been doing studies to suggest that riders’ smaller physical size plays a role in throwing off drivers’ judgements. Most interesting of all, he found that the visibility of riders depends very heavily on the background they happen to be passing at any given moment: if you’re riding in front of a white house it’s far better to wear black than so-called ‘high-visibility’ gear. To a psychologist, it's pretty obvious that visual contrast between figure and ground, rather than the rider’s clothes per se, is what will matter. But this seems to be a difficult message for wider audiences to swallow – they won't let go of the idea that ‘high-visibility’ clothing is always the best thing.

Incidentally, there are other reasons to be suspicious of high-visibility gear, not least that it transfers responsibility from the driver of the metal box that creates the danger to the victim of that danger.