The range parameter adds a departure window onto the selected departure time, or an arrival window onto the selected arrival time. With range enabled, instead of optimising solely based on the specific departure/arrival time, the model will look for any journeys that departure or arrive within the window.
Impact of using Range by endpoint
How these multiple results are then used depends on the specific API endpoint being used.
Isochrones (/time-map)
A combined shape of all possible journeys is returned.
Travel Time Matrix (/time-filter)
Multiple results are returned for each Origin-Destination pair.
Routes (/routes)
Multiple results are returned for each route.
Range Direction
The 'direction' of the range window depends on whether it is a departure search or an arrival search:
Departure Search
The window is applied 'forwards' from the departure time. For example, with a departure time of 9am and a range of 1 hour, the results with the shortest journey time departing between 9am and 10am will be returned.
Arrival Search
The window is applied 'backwards' from the arrival time. For example, with an arrival time of 9am and a range width of 1 hour, the results with the shortest journey time arriving between 8am and 9am will be returned.