[GraphHopper] rail and road

Peter graphhopper at gmx.de
Sun Feb 8 19:14:02 UTC 2015


Hi Laurent,

aha, okay.

The big problem was that sometimes rails are incorrectly mapped (?) with
including the highway tag and we wanted to make 100% sure that no car
gets on the rails, so we did:
https://github.com/graphhopper/graphhopper/blob/master/core/src/test/java/com/graphhopper/routing/util/CarFlagEncoderTest.java#L232

We were too strict at some point and had to relax this a bit, e.g. in
this issue:
https://github.com/graphhopper/graphhopper/issues/89

But I'm not sure if we can or should allow for highway & railway (??)

Regards,
Peter

On 08.02.2015 15:15, Laurent Bendel wrote:
> Hi Peter,
> no, this one’s fine. That one is the problem:
>
> http://www.openstreetmap.org/way/265979343
>
> Laurent
>
> On 8 févr. 2015, at 10:27, Peter <graphhopper at gmx.de> wrote:
>
>> Hi Laurent,
>>
>> you mean that ferry line where motor_vehicle is allowed but railway=yes?
>> http://www.openstreetmap.org/way/31100827
>>
>> Yeah it should not be excluded...
>>
>> Regards,
>> Peter
>>
>> On 07.02.2015 18:59, Laurent Bendel wrote:
>>> BTW, here’s another corner case I’ve come across: 
>>>
>>> https://graphhopper.com/maps/?point=Nakhchivan%2C%20Azerbaijan&point=41.681118%2C44.862671&layer=MapQuest
>>>
>>> The problem is, there is a small way on the end of the ferry in Turkmenbasy that is tagged both as highway=tertiary and railway=rail. The test here:
>>>
>>> https://github.com/graphhopper/graphhopper/blob/master/core/src/main/java/com/graphhopper/routing/util/CarFlagEncoder.java#L204
>>>
>>> doesn’t take this case in account. 
>>>
>>> Now, it’s true that the ferry is transporting trains, and they may share the pier at some point (à la strassenbahn) but it may be more correct to represent the road and railways as two different ways rather than a single one. But instead of splitting hairs I could just as easily edit OSM and keep the test as is (according to overpass-turbo, there are a few other cases in other places, but it seems most of them are strict railways). What do you think ?
>>>
>>> Laurent
>>>
>>>




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