<div dir="ltr"><div>Caveat - I'm not an expert in this, but seeing no other responses, thought I'd chime in with another example that might be worth examining.</div><div><br></div><div>The Golden Gate Bridge also has a reversible lane. It looks like it started by using a lanes=3 and lanes:both_ways=1 tagging scheme similar to what you outlined, but someone converted it a few years ago to use lanes=3 and lanes:conditional=4 @ ..., which seems like a nice way to be able to specify when the lane flows each direction with a syntax commonly understood by consumers of OSM data.</div><div><br></div><div>I don't know enough about how widely picked up conditional lanes or both_ways lanes are by routers, but thought I'd mention it as another example in case it's useful. <a href="https://www.openstreetmap.org/way/595194543/history">Here's a link to the history of the northbound way</a>, in case you want to take a look.<br></div><div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div><br></div>-Nick</div></div></div></div></div></div></div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Mar 22, 2023 at 10:48 PM Alan Brown via Talk-us <<a href="mailto:talk-us@openstreetmap.org">talk-us@openstreetmap.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div><div style="font-family:Helvetica Neue,Helvetica,Arial,sans-serif;font-size:16px"><div></div>
<div dir="ltr">Hi,</div><div dir="ltr"><br></div><div dir="ltr">Haven't posted to this for nearly ten years, but I figured this may be the best place to get an answer to my question.</div><div dir="ltr"><br></div><div dir="ltr">It's a question here about handling the Chesapeake Bay Bridge reversible lanes.</div><div dir="ltr"><br></div><div dir="ltr">The Chesapeake Bay Bridge has two major part, one represented by <a href="https://www.openstreetmap.org/way/27164664" rel="nofollow" target="_blank">https://www.openstreetmap.org/way/27164664</a>, another by <a href="https://www.openstreetmap.org/way/27164663" rel="nofollow" target="_blank">https://www.openstreetmap.org/way/27164663</a>.</div><div><br></div><div dir="ltr">Most of the lanes most of the time on the former side go in one direction, and the lanes on the latter side go the other direction.</div><div dir="ltr"><br></div><div dir="ltr">However - if we look at the tags on <a href="https://www.openstreetmap.org/way/27164664" rel="nofollow" target="_blank">https://www.openstreetmap.org/way/27164664</a>, we see the following:</div><div dir="ltr"><br></div><div dir="ltr"><span><table style="caption-side:bottom;background-color:rgb(248,248,255);table-layout:fixed;width:301.2px;color:rgb(33,37,41);font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,Liberation Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji;font-size:14px;border:1px solid rgb(204,204,204)"><tbody style="border-style:solid;border-width:0px"><tr style="border-style:solid;border-width:0px"><th style="border-top-color:inherit;border-right-color:inherit;border-width:0px 0px 1px;border-style:solid;border-bottom-color:rgb(204,204,204);border-left-color:inherit;width:149.8px;padding:6px 10px;white-space:pre-wrap;font-weight:500"><a title="The wiki description page for the oneway tag" href="https://wiki.openstreetmap.org/wiki/Key:oneway?uselang=en-GB" style="color:rgb(34,68,221)" rel="nofollow" target="_blank">oneway</a></th><td style="border-top-color:inherit;border-right-color:inherit;border-width:0px 0px 1px 1px;border-style:solid;border-bottom-color:rgb(204,204,204);border-left:1px solid rgb(204,204,204);width:149.8px;padding:6px 10px;white-space:pre-wrap;background-color:rgb(255,255,255)"><a title="The wiki description page for the oneway=yes tag" href="https://wiki.openstreetmap.org/wiki/Tag:oneway=yes?uselang=en-GB" style="color:rgb(34,68,221)" rel="nofollow" target="_blank">yes</a></td></tr></tbody></table></span><div><table style="caption-side:bottom;background-color:rgb(248,248,255);table-layout:fixed;width:301.2px;color:rgb(33,37,41);font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,Liberation Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji;font-size:14px;border:1px solid rgb(204,204,204)"><tbody style="border-style:solid;border-width:0px"><tr style="border-style:solid;border-width:0px"><th style="border-top-color:inherit;border-right-color:inherit;border-width:0px 0px 1px;border-style:solid;border-bottom-color:rgb(204,204,204);border-left-color:inherit;width:149.8px;padding:6px 10px;white-space:pre-wrap;font-weight:500"><a title="The wiki description page for the lanes tag" href="https://wiki.openstreetmap.org/wiki/Key:lanes?uselang=en-GB" style="color:rgb(34,68,221)" rel="nofollow" target="_blank">lanes</a></th><td style="border-top-color:inherit;border-right-color:inherit;border-width:0px 0px 1px 1px;border-style:solid;border-bottom-color:rgb(204,204,204);border-left:1px solid rgb(204,204,204);width:149.8px;padding:6px 10px;white-space:pre-wrap;background-color:rgb(255,255,255)">3</td></tr><tr style="border-style:solid;border-width:0px"><th style="border-top-color:inherit;border-right-color:inherit;border-width:0px 0px 1px;border-style:solid;border-bottom-color:rgb(204,204,204);border-left-color:inherit;width:149.8px;padding:6px 10px;white-space:pre-wrap;font-weight:500"><a title="The wiki description page for the lanes:both_ways tag" href="https://wiki.openstreetmap.org/wiki/Key:lanes:both%20ways?uselang=en-GB" style="color:rgb(34,68,221)" rel="nofollow" target="_blank">lanes:both_ways</a></th><td style="border-top-color:inherit;border-right-color:inherit;border-width:0px 0px 1px 1px;border-style:solid;border-bottom-color:rgb(204,204,204);border-left:1px solid rgb(204,204,204);width:149.8px;padding:6px 10px;white-space:pre-wrap;background-color:rgb(255,255,255)">1</td></tr><tr style="border-style:solid;border-width:0px"><th style="border-top-color:inherit;border-right-color:inherit;border-width:0px 0px 1px;border-style:solid;border-bottom-color:rgb(204,204,204);border-left-color:inherit;width:149.8px;padding:6px 10px;white-space:pre-wrap;font-weight:500"><a title="The wiki description page for the lanes:forward tag" href="https://wiki.openstreetmap.org/wiki/Key:lanes:forward?uselang=en-GB" style="color:rgb(34,68,221)" rel="nofollow" target="_blank">lanes:forward</a></th><td style="border-top-color:inherit;border-right-color:inherit;border-width:0px 0px 1px 1px;border-style:solid;border-bottom-color:rgb(204,204,204);border-left:1px solid rgb(204,204,204);width:149.8px;padding:6px 10px;white-space:pre-wrap;background-color:rgb(255,255,255)">2</td></tr></tbody></table></div><br></div><div dir="ltr">So one lane is reversible.</div><div dir="ltr"><br></div><div dir="ltr">We see this here: <a href="https://goo.gl/maps/72nEj58Qi8xiUsad6" rel="nofollow" target="_blank">https://goo.gl/maps/72nEj58Qi8xiUsad6</a></div><div><br></div><div dir="ltr">The lane is separated from others with a double yellow line - so drivers, regardless of which direction they are going, should not enter or exit it.</div><div dir="ltr"><br></div><div dir="ltr">Should this lane be digitized separately, tagged as reversible? Even though it's the same bit of pavement, it would allow routing engines that do not have lane specific routing to handle this situation. Or there another way to model this? It seems to me that the lanes:both_way tag in combination with a oneway: yes tag would be very confusing to interpret; they seem to be at odds with each other.</div><div dir="ltr"><br></div><div dir="ltr">While we're at it:</div><div dir="ltr"><br></div><div dir="ltr">I know in the past highway: motorway and highway: motorway_link ways were to be interpreted as one-way in the direction of digitization if there was no oneway tag-value pair. The latest documentation recommends marking two-way motorway_links with oneway=no. However - currently - in the absence of any oneway tag, should we still assume it is oneway? In the past, it was dangerous to, as the data was not fully attributed. But we have found some two-way motorway_links that do not have oneway=no. We can correct and tag these, but in the meantime, what should we do?</div><div dir="ltr"><br></div><div dir="ltr">Thank you for any feedback,</div><div dir="ltr">Alan </div><div><br></div><div><br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div><br></div><div> </div><div><br></div></div><div id="m_-8488445994060068812ydp8c9fba30yahoo_quoted_0157914979"><div style="font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:13px;color:rgb(38,40,42)"><div>_______________________________________________<br>Talk-us mailing list<br><a href="mailto:Talk-us@openstreetmap.org" rel="nofollow" target="_blank">Talk-us@openstreetmap.org</a><br><a href="https://lists.openstreetmap.org/listinfo/talk-us" rel="nofollow" target="_blank">https://lists.openstreetmap.org/listinfo/talk-us</a><br></div>
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