The underlying principle of highway design is that form expresses its function of moving people and goods safely and quickly between two points. Designers also agree that the highway should have a pleasing appearance. Ideally, these two principles should be united, but often they are not. Rest areas, as part of overall highway design, should express their functions as well as have a pleasing appearance. These are places where travelers stop along highways, where other functions of the road can also be revealed, such as geographic or economic gateways. They provide opportunities to showcase and clarify functions and attributes not easily presented along a linear highway. They can be subtle, inconspicuous attributes of the highway or commanding, significant statements of regional interest (Figure 20).