The trade area size and shape for any specific site is impacted by a variety of factors, including traffic patterns and shopping habits. For example, potential customers may not be willing to go off their usual driving route to access your location, or may be in the habit of driving to a specific cluster of retail outlets to do their shopping.
Additionally, there are factors that are barriers which affect the quantity and quality of the traffic for a proposed location. These barriers fall into two general categories:
1) Geographic, or natural barriers – These would include such considerations as terrain (hilly or flat), rivers, forests and lakes.
2) Physical, or man-made barriers – This type of barrier includes such things as freeways (or lack of them), railroad crossings, bridges (or lack of them), freeway overpasses and interchanges.
Each of these types of barriers can impact the volume of traffic to your location by influencing how likely your potential customer will be to visit your retail location.