You can just add the loading time to all arcs going out of the node.
In your time transit callback simply return the service time + the travel time. e.g.
int transitCallbackIndex = routing.RegisterTransitCallback(
(long fromIndex, long toIndex) => {
// Convert from routing variable Index to time matrix NodeIndex.
var fromNode = manager.IndexToNode(fromIndex);
var toNode = manager.IndexToNode(toIndex);
return data.TimeMatrix[fromNode, toNode] + data.ServiceTime[fromNode]; }
);
Could you please share some sample or link? thank you
You have a distance matrix, or some function that returns the distance between 2 nodes. Add the loading time to that computed distance.