by doing a GET-Request, I am receiving routing informations from the HERE Routing API: https://router.hereapi.com/v8/routes?apikey=MY_API_KEY&destination=52.530394,13.400683&origin=52.530728,13.383833&return=polyline,travelSummary&transportMode=truck&&vehicle[speedCap]=30&spans=names,length,duration,speedLimit Now I want to find the coordinates for example in the middle of the route with respect to the total time. So I the example below, the total duration is 274 seconds. How can I find out, on which position I will be after 137