Inner/outer Directions - Criticism and Alternatives

Criticism and Alternatives

Despite the logical benefits and uniformity of inner/outer labeling, many find the concept confusing, especially those in nations where compass directions (e.g., east and west) are by far more commonly used to sign routes (e.g. the United States). More confusion can occur in places where more than one route encircles an area (such as Houston, which is encircled by Interstate 610 and the Sam Houston Tollway); the outermost route may be called an Outer Loop and the innermost route may be called an Inner Loop (like in Rochester, New York), causing confusion with the labels. The labeling system is also rarely used, so travelers are largely unfamiliar with the terms. As a result, most applications of inner and outer are secondary to compass directions, which change as one travels along the loop.

Most beltways in the United States do not use inner/outer directions, since compass directions are the predominant way to designate direction on numbered routes. Beltways with a single number for the entire route, such as Interstate 285 in the Atlanta area, are generally given compass directions that change as one travels along the route (what would be the inner loop is instead posted as north, then east, then south, then west, and vice-versa for the outer loop).

A special case is the beltway for Minneapolis and St. Paul, which was numbered before it was common to use a single number for an entire beltway. That road is split into northern and southern halves for numbering purposes, with Interstate 694 being assigned to the northern half and Interstate 494 being assigned to the southern half. Both halves are posted with east and west directions on their entire lengths. However, the milemarkers for those Interstates treat them as a single highway, beginning at a point in the middle of I-494, increasing going clockwise and including I-694, returning to the starting point on I-494.

The Meijō Line in Nagoya, Japan uses the terms clockwise and counterclockwise.

Hong Kong's Transport Department employs yet another method of orbital road signing: clockwise traffic on Route 9 is denoted by the letter "A", while counterclockwise traffic is denoted by the letter "B".