Detour

A detour is a route that deviates from the direct or planned path, typically used to bypass an obstacle, hazard, or obstruction. In everyday language, a detour refers to any temporary change of route, while in specific contexts it can describe longer-term diversions around construction or events.

In road traffic, detours are usually temporary and are established during road work, accidents, road closures, or emergencies. Detour routes are marked with signs, barriers, and sometimes digital signals, guiding drivers along alternate streets. The duration and chosen path depend on safety, traffic volumes, and local geography. Detours can affect travel times, access to neighborhoods, and public services, and drivers are advised to follow posted detour instructions and observe traffic rules.

In navigation and planning, detours may be planned or generated by route-planning tools when the direct path is unavailable. Some apps allow detour avoidance preferences, while still offering an alternative route if a blockage occurs.

In mathematics and computer science, a detour refers to a path between two vertices that is not the shortest possible, or more generally to any route that runs through more edges than necessary. In graph theory, a detour is contrasted with a shortest-path route, and it is a useful concept in analyses of network reliability and routing algorithms.

Detours are part of transportation engineering, public safety, and spatial planning, and their success depends on clear communication, appropriate signage, and consideration of pedestrian and emergency access.