This chapter concerns the question of how people navigate through a space in which other people are also present. Issues addressed include how the space itself affects the way people navigate, how this is changed by the presence of others in the space on a collective or individual basis, and how navigational abilities and behaviour can be measured. Such measurements can then be used, for example, to identify aberrant behaviour in public spaces. The state-of-the-art and current challenges in this domain are discussed. A new empirical approach to the tracking of pedestrians who are navigating populated spaces is then described, and its verification, validation, and further extension discussed.
Regardless of our ability, most of us have had to navigate through a space in which other people are also present. For most, this is simply achieved by walking through the space. For others, with some form of movement disability, this may be achieved with the help of others, who may undertake the navigation. Thus, we can argue that the vast majority of people have had some experience of navigating a space. This then leads to the simple question; how do we navigate through a space? In attempting an answer, we actually find ourselves posing yet further, more complex questions.
How does the space affect the way people navigate?
How do other people in a space change the way they individually and collectively navigate a space?
How do individuals and groups mitigate the effect of others in a space?
Finally, perhaps most importantly, can our learnt navigational ability be measured in some way so we can better understand the mechanisms involved in navigating a space and if so, will it help us answer the preceding questions? If we are able to undertake this measurement then perhaps we might be able to design better spaces.
The underlying premise is that navigational skill is a learnt capability, developed over many years from our initial faltering steps as a toddler, through childhood and into adulthood. We can also reflect that even parents have to develop new navigational skills as they seek a path through a space that is more appropriate for any child for whom they are responsible, especially if that child is in pram or buggy.Top
What Can Be Measured?
We have to be realistic as to what can be measured, and not attempt to measure aspects that are innate to an individual. Thus, we can measure instantaneous speed and average speed over some observed path, but we cannot measure the speed at which a person would like to walk. We can measure the distance at which a person deviates from a given path to avoid another stationary or moving obstruction to their progress, but not the distance at which they become aware of the obstruction. We cannot measure a person’s desired personal space, but we can measure the gap they keep to anybody they are following, also known as their headway. We can also measure the distance between the shoulders of two people either as one overtakes the other or when they are moving towards each other. When avoiding an obstruction, we can see if a person deviates to the left or right, but we cannot measure their propensity to move to the left or right when avoiding an obstruction. We could measure acceleration but is that critical, given that most people appear to be able to go from rest to a normal walking speed or vice-versa in one step. Perhaps the most crucial aspect of measurement is to ensure the process itself does not perturb the space in any way. If it does, then the measurements themselves will be unrepresentative, and it will be very difficult to obtain any valid results and then infer any conclusions from the measurements. The aim of the measurement process should be to determine the distribution of each possible measurement across the population and to understand how these distributions vary with different types of people and space.