jalons

A jalon is a marker placed along a route to indicate distance, position, or progress. The term comes from the French jalon, meaning a marking or post along a road. In English usage the word is occasional, with milestone as the more common equivalent.

Jalons have been used in various contexts to aid navigation, measurement, and planning. Historically, they appeared along roads, canals, and railways to show distance from a fixed origin and to serve as reference points for travelers and officials. In cartography and surveying, jalons can function as control points used to fix geographic coordinates and to calibrate maps. Archaeological and historical studies sometimes refer to ancient markers along great routes as jalons in a descriptive sense.

In modern practice, jalons are often synonymous with milestones. In project management and program planning, a jalon marks a significant event, phase, or deliverable that indicates progress toward objectives. In geographic information systems and navigation, digital jalons or waypoints facilitate travel routing, data collection, and spatial analysis.

Characteristics of jalons vary by region and purpose. Physical jalons may be posts, stones, plaques, or painted markers bearing distance figures in kilometers or miles. The concept also encompasses non-physical markers, such as printed or digital indicators used in maps and planning documents. Overall, jalons serve as practical reference points that help orient users, measure distance, and organize sequences of steps or events.