A polygon representing the area reachable from a point within a given travel time or distance threshold used in site selection and trade area modeling.
An isochrone drawn for “15 minutes by car” will rarely be a clean circle, it stretches further along highways and contracts around natural barriers like rivers or dense urban blocks which makes it a far more realistic trade-area boundary for site selection than a fixed-radius circle.
Further reading: Geo layer · Retail site selection
