This article applies to the following API endpoints:
Every search using one of these 3 endpoints is either a Departure search, or an Arrival search. Which of these is used has an impact on the following:
Direction of travel
When generating isochrones (/v4/time-map) a Departure search finds the area that is reachable when travelling away from the search location. An Arrival search finds the reachable area when travelling towards the search location.
Departure / Arrival time
For a Departure search, journeys are calculated with a chosen departure time. For an Arrival search, journeys are calculated with a fixed arrival time.
One-to-many vs Many-to-one
When generating travel time matrices (/v4/time-filter), a Departure search runs a one-to-many search, calculating the travel times from one origin to multiple destinations (up to 2,000 per search). An Arrival search runs a many-to-one search, calculating the travel times from multiple origins (up to 2,000 per search) to one destination.