The efficiency and walking speed of visually impaired people

Abstract
All pedestrians have a walking speed which they prefer. This appears to be the speed which, for them, is the most physically efficient. Blind pedestrians, if allowed to set the pace when accompanied by a sighted guide, will prefer to walk at a speed which is close to that of sighted pedestrians. However, when walking independently they adopt a pace which is slower than their preferred walking speed. By converting adopted walking speed into a proportion of preferred walking speed we are able to show that subject data may be pooled and comparisons made which had hitherto been impossible. Furthermore, statements may be made about the physiological efficiency of a performance. For example, efficiency varies with route difficulty, increases with increased preview, and only users of guide dogs reach their optimum efficiency.