The options available for observing alternative routes. The RouteOptions used to set the current active route are updated according to the current route progress.
Register your RouteAlternativesObserver through MapboxNavigation, the onRouteAlternatives callback will be triggered every intervalMillis. There are multiple conditions that will disable alternative route requests:
There are no observers registered
There is not an active route
The trip session is not started
The interval in milliseconds, default is 5 min.