<html><head></head><body><div class="ydp77cdb0a2yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><div></div> <div>Hi,<br><br>First: the interpretations given here to 'tunnel' are much more strict than the wiki, which leaves much more room for interpretation. A strict interpretation of tunnel makes the use of tunnel=yes of tunnel=culvert for passages of rivers underneath a road senseless, just as tunnel=building_passage.<br><br>Second, I hope that you are aware of the consequences of your interpretations. Let's use the definition of Marc, which is the most elaborated: "I apply the rule: stand on the road, look up, which layers of material do you "see" before you reach the sky? Is there earth (grond/aarde) that was not placed there artificially, then you are in a tunnel.": Then the 'railroad tunnel' between Brussels North and Brussels South is NOT a tunnel. It is just a mole pipe (in the words of Gerard). The whole thing is dug out, built and then covered with streets, buildings and here there a bit of gorund.<br>Even a lot of the metrotunnels are made with the 'cut and cover' technique and are thus NO tunnels? Ecoduct Kikbeekbron over the E314 is NOT a tunnel?<br><div>Also the examples given by Marc and Tim with such a thin cover are most likely made 'cut and cover' and have only 'artificial' things overneath: NO tunnels...</div><div>And what do you do with the GEN-constructions at railway 161 in Genval? The railway has been covered with roads and parking lots. Also no tunnels? <br></div><div>On the other hand: ecoduct Groenendaal really looks like a bridge but has been mapped as a tunnel...<br></div><br>Lionel said : "A tunnel is generally something that was dig (removing earth/material) and consolidated from the inside (most often with concrete) like a subway tunnel if you want. It seems pretty rare to dig a big hole, make a tunnel and put back the earth on top !": Yet, that ís a very common practice...<br><br>So to me these seem to be useless definitions...<br><br>Or does the word 'artificial' means that ground level matters? The ringway around Antwerp (R1) is almost everywhere at level -1, below ground level. The cutting is here the artificial structure (using Yves' words this time). So where there is a road going overneath, the ringway goes through a tunnel...? The same for Joost's example: if you look at the aerial imagery, you can see clearly they had to dig out the N28 to get underneath the railway and the other roads: thus a tunnel...? And what about the complex traffic changers where it is often very hard to see what the original ground level was.<br><br>@ Yves: 'Layer' gives a relative position. Something at ground level can perfectly have layer=-1 or layer=1. Check the wiki. And further: a bridge with layer = 1 doesn't mean it is above ground level; a tunnel with layer = -1 doesn't mean it is below ground level.<br><br>@ Tim: What came first is a useless criterion. The E313 was constructed before the E314, but it is definitely a bridge of the E313 above the E314. And the definitions of bridge or a tunnel should be so that anyone knows whether to map things as bridge or tunnel without having to know in which order roads, railways, etc. were constructed.<br><br>So can someone can come up with a useful definition?<br><br><div>Can I come up with a definition? I like the length/width ratio, the open bridge(like) structure against a confined tunnel(like) structure. And <span>the fuzziness of the wiki. But one thing is very clear for me: ground level doesn't matter.</span></div><div><span> <br></span></div><div><span>Regards,</span></div><div><span><br></span></div><div><span>StijnRR<br></span></div><br></div><br><div><br></div>
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Op dinsdag 28 mei 2019 18:52:50 CEST schreef Marc Gemis <marc.gemis@gmail.com>:
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<div><div dir="ltr">This is the place:<br clear="none"><a shape="rect" href="https://www.google.com/maps/@51.2216551,4.0345363,3a,75y,49.39h,77.96t/data=!3m6!1e1!3m4!1sjggCIzrpgLhVFtrn6gYCnQ!2e0!7i13312!8i6656" rel="nofollow" target="_blank">https://www.google.com/maps/@51.2216551,4.0345363,3a,75y,49.39h,77.96t/data=!3m6!1e1!3m4!1sjggCIzrpgLhVFtrn6gYCnQ!2e0!7i13312!8i6656</a><br clear="none">(sorry no Mapillary images yet).<br clear="none"><br clear="none">Burchtakker (the parallel road) is lowered near the (bicycle) tunnel<br clear="none">under the E34/A11.<br clear="none"><div class="ydp1d350bc3yqt8281702463" id="ydp1d350bc3yqtfd21451"><br clear="none">On Tue, May 28, 2019 at 6:36 PM Marc Gemis <<a shape="rect" href="mailto:marc.gemis@gmail.com" rel="nofollow" target="_blank">marc.gemis@gmail.com</a>> wrote:<br clear="none">><br clear="none">> I think there is a tunnel under the e34 between Antwerpen en Zelzate. There used to be a level crossing which was removed and instead they created an underground passage for it.<br clear="none">><br clear="none">> M<br clear="none">><br clear="none">> Op di 28 mei 2019 14:46 schreef Lionel Giard <<a shape="rect" href="mailto:lionel.giard@gmail.com" rel="nofollow" target="_blank">lionel.giard@gmail.com</a>>:<br clear="none">>><br clear="none">>> @joost schouppe To me that's indeed a bridge, as you see the same structure as on the motorway bridges : a platform supported by pillars....<br clear="none">>><br clear="none">>> A tunnel is generally something that was dig (removing earth/material) and consolidated from the inside (most often with concrete) like a subway tunnel if you want. It seems pretty rare to dig a big hole, make a tunnel and put back the earth on top ! ;-)<br clear="none">>><br clear="none">>> I can't find example of tunnels that's really like "under a railway or motorway", so i would say that probably 99% of the tunnel are below ground or mountains/hills (if we exclude the obvious building passage that we classify as tunnel in OSM). They are generally longer than wide as someone quoted from wikipedia.<br clear="none">>><br clear="none">>> _______________________________________________<br clear="none">>> Talk-be mailing list<br clear="none">>> <a shape="rect" href="mailto:Talk-be@openstreetmap.org" rel="nofollow" target="_blank">Talk-be@openstreetmap.org</a><br clear="none">>> <a shape="rect" href="https://lists.openstreetmap.org/listinfo/talk-be" rel="nofollow" target="_blank">https://lists.openstreetmap.org/listinfo/talk-be</a><br clear="none"><br clear="none">_______________________________________________<br clear="none">Talk-be mailing list<br clear="none"><a shape="rect" href="mailto:Talk-be@openstreetmap.org" rel="nofollow" target="_blank">Talk-be@openstreetmap.org</a><br clear="none"><a shape="rect" href="https://lists.openstreetmap.org/listinfo/talk-be" rel="nofollow" target="_blank">https://lists.openstreetmap.org/listinfo/talk-be</a><br clear="none"></div></div></div>
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