I like walking because it is slow, and I suspect that the mind, like the feet, works at about three miles an hour.
—Rebecca Solnit. Wanderlust
While walking, we see a great deal more of our surroundings in greater detail and with more engagement of our senses than when we are in a car, so we seek path surroundings that are varied, detailed, and sensual. It’s the difference between an environment designed to be seen at 30 kilometers an hour and one designed to be seen at 5 kilometers an hour. In Cities for People, the Danish architect Jan Gehl states, “Our sensory apparatus and systems for interpreting sensory impressions are adapted to walking….We have to slow down to about 5 km/h [3 mph] to grasp the overall picture as well as the details.”
Higher speeds alter what we see in almost every way. The human eye and mind can register about three objects a second. As a result, a motorist passing a 10-meter-wide shop at 40 khr/25 mph can distinguish 3 objects. A bicyclist pedaling at 16 khr/10mph an hour past the same shop can make out about 6 features, while a pedestrian walking by at an average 5 khr/3 mph can perceive 21 elements. Providing fewer than three elements per second for walkers prompts boredom, as anyone knows who has walked beside a flat modern façade.
Moving at any speed, we stare far enough ahead to detect any looming problem in time to avoid it. The faster we move the farther ahead we need to focus. This combined with reduced viewing time means that at higher speeds larger objects must be placed farther from us to be observable. Moreover, looking at objects through the windshield frame flattens them and makes them cinematic—they cannot be touched or experienced, only viewed “on the screen.”
By contrast, when standing or walking, we can see everything from close-up building details to far mountains. Although we remain focused ahead, our cone of vision widens so we can see things to the left and right, down to our feet and up to the clouds. Our spatial perception improves as well—we usually see both the side of an object on approach and the front passing by. Thus, for walkers, space ahead is easily and fully observed.
While walking we take a special interest in people around us. At farther distances, we note their overall size and shape. As they approach, we watch first their gestures, and then, more especially, their facial expressions. In inanimate surroundings, our interest goes to pavement and borders. In pavements we are concerned with smoothness and slope and enjoy the details of patterning. In borders we are drawn especially to in-and-out edges that provide sheltered niches for standing, leaning, sitting, and looking out onto the path and surroundings.
“In old cities where traffic was based on walking,” Gehl notes, “space and buildings were designed … based on a cornucopia of sensory impressions, spaces are small, buildings are close together and the combination of detail, faces and activities contributes to the rich and intense sensory experience.…”
This design understanding was applied in Central Park, for instance, where path surroundings differed along the separate circulation systems for carriages, walkers, and horse riders. As Elizabeth Barlow Rogers pointed out in the park’s restoration plan, landscapes “adjacent to the Drives were broad and sweeping; beside the paths were intimate in scale and detailed in design; along the Bridle Trail they became rugged and picturesque.”
In more recent years, the science of chaos has offered a model for handling the multiple levels of detail a walker can appreciate. However closely we observe anything in nature—a rock, a tree, a cloud—there is always a new level of complexity to enjoy. Chaos says that we can never find a microscope so powerful that we fail to find a new, smaller scale of detail, which is a major reason why nature is endlessly fascinating.
This natural complexity stands in marked contrast to most human-made objects in the landscape—think building wall, sign, or paving, which are architected large, simple, and flat for viewing from vehicles. As Gehl observes, “Taking a walk in 60 km/h (37 mph) architecture is an impoverished sensory experience: uninteresting and tiring.”