Isoline can be calculated in the reverse direction. It answers the question: From where can I get to the destination within given range. This can be for example useful to determine which vehicles from a fleet of vehicles (Taxi service) can get to the destination within given time. To trigger calculation in reverse direction, use destination parameter instead of start.

https://isoline.route.api.here.com/routing/7.2/calculateisoline.json
?app_id={YOUR_APP_ID}
&app_code={YOUR_APP_CODE}
&mode=fastest;car;traffic:disabled
&rangetype=time
&destination=geo!52.51578,13.37749
&range=600

Figure 1. Example reverse direction isoline representing a travel time of 10 minutes to the center of Berlin.