It is possible to create a larger influence of the heading on the routing. However, I am not yet 100% convinced we should do that.
This can lead to significant and potentially frustrating detours, often unintentional.
Unfortunately, we currently don’t have the option to provide nice u-turn announcements where we search for a good intersection to turn around.
So if we enforce the heading in the above example the route would lead through Hohenkammern and Allershausen, instead of turning around and following the side road with almost no cities.
This example is certainly arguable, so the detour is not too bad either and in a large group I might rather take the detour than turning around. If you slightly move the start or destination then the detour is chosen.
Enforcing the heading in a different example, for example here in the alps, driving to the west, would lead to a 100km detour. In the alps there are thousands of such cases where the routing would end up using huge detours. So enforcing the heading is no option.
Slightly increasing the impact of the heading is something we can discuss about and we should think about how much detour we would like to accept. 5min? 10min? 7km? 50km?
With a motorcycle turning around is fast and easy and you don’t need a lot of space. So this is different to truck routing where turning around is no option.