[GraphHopper] Bigger penalty for ferries?

[Peter K]

Hi Thomas,

>> You could try locally if this fixes the problem. But even if it does, we
>> probably should think about a better solution.
>>
>
> Hi Peter, thanks for your help, the change seems to do the trick in this case.
>
> Perhaps one could make some educated guess on how much time a
> ferry-crossing will take based on the estimated_distance. But still,
> there are so many other factors that can disrupt a ferry-crossing -
> while this ferry in particular fares all day in either direction as
> soon as it has loaded a few passengers, others follow a set schedule,
> and a schedule which is limited to certain hours of the day at that.

Well, at the end you can also have a traffic jam etc. So the calculated 
time is of course only an estimation. And one has to think about if the 
costs of calculating this estimation is worth the trouble.


> Perhaps it would be possible to build multiple indexes/graphs, one
> that accommodates avoiding ferries, another one that optimises for
> distance instead of speed, etc.

If you use CH that is the only possibility. If you use a simple 
dijkstra you can do everything per query.

Regards,
Peter.