Successive 90 minute isochrones,
centred on Brussels Airport,
assuming lorry speeds

Isochrones are contours representing the distance it is possible to travel from a particular location within a given period of time. It is necessary to make assumptions about average vehicle speeds for different road types. In this case it is also necessary to represent average ferry crossing speeds and waiting times.

The contours spike outwards where rapid movement is possible. Typically, these are locations of motorways or dual carriageways.

Isochrones are often used in conjunction with Depot Location Software