The map that I'm working on has a pedestrian area. I'm trying to route from a point near there to another spot on the map but because the pedestrian area isn't connected to the rest of the streets, the routing algorithm gives up.

Should the map be modified to connect the pedestrian area to the road near it? Or is there some appropriate fix in the routing algorithm?

Edit: Here's an example:

http://www.yournavigation.org/?flat=32.122709107475&flon=34.817094386304&tlat=32.1092743&tlon=34.8398295&v=foot&fast=1&layer=mapnik

Move the red marker around and you can see that when it looks for the closest node, sometimes it find a small, four-sided pedestrian area that has no path to the rest of the map. yournavigation.org is using pyroute as far as I can tell.

asked 25 Jul '11, 18:37

eyal0's gravatar image

eyal0
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accept rate: 0%

edited 26 Jul '11, 09:03


If the pedestrian area is connected to the road, you should add those connections to OSM. Sometimes it may be necessary for those areas parallel to a road to add either additional, somewhat artificial ways between them or directly connect them along a whole side with the road.

Routing engines need these kind of ways. If they will start doing approximations instead, they may also route you along ways that are impassable in reality. You don't want that either.

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answered 25 Jul '11, 19:09

scai's gravatar image

scai ♦
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If the area is connected in reality, you should connect it also in OSM. Routing algorithms can't assume connections, because some areas are not connected in reality.

Be sure to draw the pedestrian areas at their actual position (i.e. draw the actual borders, as it is a polygon and not a center line). Usually if there is car traffic going over the area (you will draw explicit roads for this crossing the area) you get a lot of intersections each of which should be connections (nodes).

If you can't deal otherwise in an appropriate manner with the situation, you will have to draw short explicit "virtual" connections (footways or similar) to connect the roads with the area, like @scai suggested.

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answered 26 Jul '11, 18:15

dieterdreist's gravatar image

dieterdreist
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Without knowing what area you are talking about it is hard to dertermine wether it is tagged correct. However there are many pedestrian areas that are not connected with the surrounding streets.

The routing engine should probably consider the case you are describing. It is hard to help you any more without knowing what routing engine and the area you are talking about.

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answered 25 Jul '11, 18:57

Gnonthgol's gravatar image

Gnonthgol ♦
13.6k15101198
accept rate: 16%

1

I added an example to the question.

(26 Jul '11, 09:03) eyal0
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question asked: 25 Jul '11, 18:37

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last updated: 26 Jul '11, 18:15

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