The gravity of the situation

Also, the gravity model of migration involves an inverse square relationship, based on universal gravitation, which describes how people are more likely to go here or there, within a "sphere of influence", and is used to estimate traffic flow as well. In traffic flow, 'the inverse of density is spacing, which is the center-to-center distance between two vehicles'.

"The essential feature of Newton's Law of Universal Gravitation is that the force of gravity between two objects is inversely proportional to the square of the distance between them. Such a connection is known as an "inverse square" relationship. Newton derived this relationship from Kepler's assertion that the planets follow elliptical orbits. To understand this, consider the light radiating from the surface of the sun. The light has some intensity at the surface of the sun. As the light travels away from the sun, its intensity diminishes. The intensity of the light at any distance away from the sun equals the strength of the source divided by the surface area of a sphere surrounding the sun at that radius.

As the distance away from the sun doubles, the area of the sphere surrounding the sun quadruples. Thus, the intensity of the sun's light depends inversely on the square of the distance away from the sun. Newton envisioned the gravitational force as radiating equally in all directions from a central body, just as sunlight in the previous example. Newton recognized that his gravitational model must take the form of an inverse square relationship. Such a model predicts that the orbits of objects around a central body will be conic sections, and years of astronomical observations have borne this out . . ."

"We sense gravitation only when masses like that of Earth are involved. The force of attraction between you and a classmate is too weak to notice (but it’s there!). The force of attraction between you and Earth, however, is easy to notice. It is your weight. In addition to your mass, your weight also depends on your distance from the center of Earth. At the top of a mountain, your mass is the same as it is anywhere else, but your weight is slightly less than at ground level. Your weight is less because your distance from the center of Earth is greater . . ."

 

The attractive forces at play may be relatively small, but as they are predominant for being universal (and never sleep, that is), when things like steering wheels are powered to be influenced so easily, I guess it's still plausible that gravity could attract otherwise aimless vehicles to one another.

"The constant G is called the universal gravitational constant and Cavendish determined it. The word 'universal' indicates that scientists think that this constant applies to masses of any composition and that it is the same throughout the Universe. The value of G is an incredibly small number, showing that the force of gravity is very weak. The attraction between masses as small as our bodies, or even objects the size of skyscrapers, is incredibly small. For example, two 1.0-kg masses located 1.0 meter apart exert a force on each other the weight of a typical grain of pollen.

Although gravity is the weakest of the four fundamental forces of nature, its attractive nature is what holds us to Earth, causes the planets to orbit the Sun and the Sun to orbit our galaxy, and binds galaxies into clusters, ranging from a few to millions. Gravity is the force that forms the Universe . . ."

 

For the sake of comparison, a concept of herd behavior in everyday decision-making is similar to the aforementioned gravity model of migration (so it seems the herd mentailty may be thought of as another kind of gravitation), and each body in a herd is attracted to others by the pull of gravity to some extent, anyway.

Herd Behavior
"Benign herding behaviors may occur frequently in everyday decisions based on learning from the information of others, as when a person on the street decides which of two restaurants to dine in. Suppose that both look appealing, but both are empty because it is early evening; so at random, this person chooses restaurant A. Soon a couple walks down the same street in search of a place to eat. They see that restaurant A has customers while B is empty, and choose A on the assumption that having customers makes it the better choice. Because other passersby do the same thing into the evening, restaurant A does more business that night than B."

Gravity Migration
"When used geographically, the words 'bodies' and 'masses' are replaced by 'locations' and 'importance' respectively, where importance can be measured in terms of population numbers, gross domestic product, or other appropriate variables. The gravity model of migration is therefore based upon the idea that as the importance of one or both of the location increases, there will also be an increase in movement between them. The farther apart the two locations are, however, the movement between them will be less. This phenomenon is known as distance decay."

So the mental attraction of a particular area in a parking lot could be described by either of those ideas, which correspond to the physical concept of gravity, in a predictable way.

Etc.
This kind of virtual gravitation is related to trucking in other ways too: "A gravity model in transportation conforms to the general notion of how one might consider cargo flows to be apportioned between producers and consumers. The shorter the distance between an origin-destination pair, the greater the likely cargo flow between them. Also, the larger the industrial activity in the origin-destination pair, the greater the likely cargo flow between them. This is a widely applied and accepted model and has been shown to be a fairly good predictor of movements . . ."

Gravity isn't necessarily the only thing that attracts or influences movement. The colors of flowers attracting hummingbirds, for example, or the wind and weather pushing vehicles around, which may be considered separately. I think people tend to magnify the gravitational patterns though, so it's a wonder whether their physical or mental attraction to other objects is to be distinguished. Naturally they shouldn't want to slam into a truck, or get into a hundred car pile up, yet they do it all the time (as if it were the same as looking for a parking place)...

"In the oft cited article 'Geometry For The Selfish Herd', evolutionary biologist W. D. Hamilton asserted that each individual group member reduces the danger to itself by moving as close as possible to the center of the fleeing group. Thus the herd appears as a unit in moving together, but its function emerges from the uncoordinated behavior of self-serving individuals."

This sounds a lot like the pull of gravity (toward the center mass), so a herd of animals in the wild (or driving down the road) seems to follow a gravitational pattern with that mentality, or without even thinking too.

Basically, since gravitation compels dispersed matter to coalesce, I think that dispersed matter coalescing resembles gravitation. That's what led me to look it up anyway, and there were more examples than I'd imagined. Of course, I wasn't thinking to myself "look, dispersed matter is coalescing around the parking lot" (but I am now)! Well, I probably won't remember that phrase, just the gravity of the situation.