The callback function specified in the VERouteOptions.RouteCallback Property of the VERouteOptions object passed to the options parameter receives a VERoute Class object containing route details, including the step-by-step route directions.
If the locations parameter length is greater than 25, an empty VERoute object will be returned. An empty VERoute object has no itinerary and the VERoute.Distance Property and VERoute.Time Property are 0.
If one or more of the points specified in the locations parameter is not found, then null will be returned to the callback function.
If the VERouteOptions.RouteMode Property is set to VERouteMode.Walking, an empty VERoute object will be returned if the total route distance between the start and end points is greater than 16 kilometers. This total route distance includes portions of the route where you may not be walking. For example, ferry segments of the route are included in the total route distance.