Until now, the major obstacle that has prevented people from thinking critically about stray shopping carts has been that we have not had any formalized language to differentiate one shopping cart from another.

In order to encourage a more nuanced and comprehensive understanding of the phenomenon, I have worked for the past six years to develop a system of identification for stray shopping carts. Unlike a Linaean taxonomy, which is based on the shared physical characteristics of living things, this system works by defining the various states and situations in which stray shopping carts can be found. The categories of classification were arrived at by observing shopping carts in different situations and considering the conditions and human motives that have placed carts in specific situations and the potential for a cart to transition from one situation to another.

The resulting Stray Shopping Cart Identification System consists of two classes and thirty-three subtypes that can be used singly or in combination to describe and thereby “identify” any found cart. One of the unfortunate difficulties in implementing a situational taxonomy of this kind is that one is often required to speculate about where a cart is coming from and where it is going next. While this uncertainty can at times be vexing, it must be remembered that this system is the first attempt to categorize and analyze the transient nature of the shopping cart. The refinement of this system is an ongoing process.

Because the Stray Shopping Cart Identification System considers the situation a stray cart is in and the potential to transition to new situations, it is often not possible to assign Type designations with complete certainty. Some Types, B/2 DAMAGED for example, describe the physical condition the stray cart is in; consequently it is relatively easy to assign the B/2 Type designation. Types that describe a cart’s situation in a larger context (A/9 REMOTE FALSE, B/1 OPEN TRUE, and many others) cannot be assigned with certainty without actively tracking the cart for days or weeks. With long-term tracking often being out of the question, the observer should take into account the context in which he/she finds the cart and construct a likely hypothesis.

One must keep in mind that a number of Types have significant overlap in their definitions. For example, a B/3 FRAGMENT is by definition also a B/2 DAMAGED. Similarly, B/10 PLOW CRUSH and B/11 TRAIN DAMAGED are also B/2 DAMAGED. The overlap is useful in situations where the specific cause of the damage cannot be determined. In such cases, the B/2 Type alone should be assigned. At some level, it would be correct to think of B/3, B/10, B/11, and B/20 as subtypes of B/2. However, given that this System is based on the situation in which a cart is found, these Types must be separate. When assigning Type designations, it is not necessary to assign redundant Types. For example, one does not need to assign B/2 DAMAGED as well as B/10 PLOW CRUSH.

Another aspect of the identification process is that a cart may hold multiple Type designations. For example, a B/14 Archaic cart can simultaneously be a B/10 PLOW CRUSH. Some Type designations, once acquired by a specimen, are retained (indicated by the R–Arrow icon) throughout all subsequent transitions, while others are lost when a transition occurs. For example, if a B/3 FRAGMENT is thrown in the trash, it will acquire the B/19 IN/AS REFUSE designation, but it will still retain the B/3 designation. When a B/4 ON/AS PERSONAL PROPERTY is removed from personal property, the designation is not retained. A general rule is that physically damaged or modified carts retain the Types that affected them, while those Types based purely on the situational context in which they are found are lost when a transition to a new situation occurs. One Type outside of this dichotomy is B/14 Archaic, which is always retained since it is defined by the irreversible event of its SOURCE of origin closing.

CLASS A Types can be subject to some CLASS B Types. A common example is that when an A/1 CLOSE FALSE is vandalized at the edge of the SOURCE lot, it acquires the secondary Type of B/12 SIMPLE VANDALISM. Such situations are indicated by a green icon with a brown border. A CLASS B cart can acquire a CLASS A Type only when a B/1 OPEN TRUE is left at a bus stop, where it becomes A/3 BUS STOP DISCARD.

Vacant lots, ditches, spaces between buildings, behind buildings, under bridges and overpasses, and all manner of vacant gaps between properties, public or private.

The primary research for the development of the Stray Shopping Cart Identification System was done in Buffalo, New York, over the course of six years. The Buffalo area was used as a systemic template due to its high level of cart activity and the drastic seasonal changes that allow the presence of snow-related Types. Further research and experimental applications of the System have been done at various locations in the Eastern United States and Southern Canada. While the System appears to work in most locations in the East, there is the possibility that some regions may possess conditions and forces not considered in the present version. The System is not closed and new discoveries that do not fall under the currently defined Types will demand the establishment of new Types.

WESTERN NORTH AMERICA
Although the System has not been tested or widely applied in the Western United States, Canada, or Mexico, it is probable that the System in its present form would encompass the majority of Western stray cart activity. Recent research done on the Hawaiian islands of Oahu and Maui prove that the System is fully applicable at the most remote western reaches of the United States.

EUROPE
Travels abroad have confirmed that the System of Identification functions beyond the North American continent. FALSE and TRUE strays were found in three Scandinavian capitals: Copenhagen, Oslo, and Stockholm, and on the Swedish island of Gotland (See the Observing Carts in Scandinavia page). While the stray activity in these cities differs in intensity from that of an Eastern North American city, the basic Type designations of the System appear to accurately describe it. There was, however, one important exception found in Copenhagen (See the Observing Carts in Scandinavia page). Anecdotal reports from elsewhere in Europe suggest that the System may function across Western Europe. A recent search for stray shopping carts in Moscow turned up almost no results, why this is the case is not yet understood.

ASIA, AUSTRALIA, SOUTH AMERICA
The System has not yet been tested on these continents. I have been sent photographs of what appear to be stray shopping carts from both Japan and Australia, but no rigorous investigations have taken place. I have also heard of wide spread stray activity in Argentina, but I have not seen any documentation.