nondetour

Nondetour is a neologism used in discussions of route and path planning to describe a path that adheres to a predefined detour tolerance while meeting essential constraints. The concept treats detour as a measurable deviation from a reference path, typically the shortest possible route, and seeks to minimize that deviation without compromising requirements such as safety, time windows, or resource limits.

Etymology and usage are informal; the term combines the negation of detour with the idea of staying close to an intended route. In practice, nondetour is discussed when designers want to avoid unnecessary circuitous routing or excessive risk, while still allowing deviations when necessary to accommodate obstacles, constraints, or dynamic conditions. It is commonly invoked in fields such as autonomous navigation, logistics routing, and robotic path planning, where a balance must be struck between optimality and practicality.

Formalization often involves a detour ratio, defined as the excess length of a candidate path over the length of the shortest feasible path, relative to the latter. A path may be described as nondetour if its detour ratio stays below a specified tolerance and the path satisfies all governing constraints. Some formulations also require nondetour paths to be robust to small perturbations, ensuring that minor changes in the environment do not force large, undesirable detours.

Limitations include the potential trade-off between strict nondetour adherence and objective measures such as total travel time or energy consumption. In dynamic environments, maintaining nondetour can be challenging, and practical systems may employ adaptive tolerances or probabilistic strategies.

See also: detour, shortest path problem, route optimization, path planning, detour tolerance.