Hi Bernd,
basically, there are two things to take into consideration
1. how Guided Navigation works
in Guided Navigation, we artificially lower the routing costs for certain segments of the map. This means that even a small, slow or simply irrelevant road will "look more appealing" to PTV Navigator than it would if we´d just look at the map data - because the costs to take these roads is suddenly less than it normally is
2. how we avoid Traffic Jams
We regularly check for traffic jam updates and - if one incident comes up or grows bigger on the current trip - we then compare the increased ETA of the route with the bigger traffic Jam with the ETA of possible alternative routes. If the difference we find crosses a certain threshold (our default is: 5 minutes) we will offer the user the alternative route we found and he can decide if he wants to take it.
Now think of this: the route we calculate with guided Navigation is the most attractive one in terms of costs.
I a traffic jam comes up on this route, the costs for this route will rise, yes, but as we started with a very low initial cost it will be rather difficult to leave the Guided Navigation.
So, long story stort: both Guided Navigation and Traffic Jam avoidance are very smart but also very trick to predict in theory (as so many factors like for example simply the length of the route are important for the calculation).
What a user should think of is: do I want to stay on a route if there is a small traffic jam? when (=with which ETA-increase) so I want to see a new route? Then, based on this decision, you can set the threshold for when we look for a alternative route.
what do you think?
or
