Proposal talk:Two way lane

key name

'reversible' or 'reversible_lane' may not be the best choice.

The lanes have in common that their traffic flow is either time/signal dependent or it can be used from both sides. In other words: Neither 'forward' nor 'backward' can be used to describe their traffic flow.

'reversible' more related to the first type of lanes (time dependent). Thus my more neutral key name proposal would be:

both_way_lane=median / passing / tidal_flow / no

'no' may be assumed for a highway without both_way_lane tag. 'tidal_flow' instead of 'reversible' because OSM uses British English.--Martinq 10:34, 26 March 2012 (BST)

Any native speakers around? Any suggestions for a better sounding and intuitive name? Even the all-knowing wiki calls them reversible lanes with the variation of median and passing lanes. Maybe two_way_lane? --Imagic 12:44, 26 March 2012 (BST)

Australian here. I've never heard the term "tidal flow", although we have several of these lanes here (Melbourne). OSM is not "British English" - it's a weird amalgam of British English, US English, German English, French English... I think "reversible_lane" is much clearer, and more widely understood than "tidal flow" (which sounds, let's face it, like a river).

I'm not really down with lane tagging, but wouldn't a single, unified system like "lanes=forward|forward|reversible|backward|backward" or even "lanes=2|reversible|2" be best? Stevage 01:43, 27 March 2012 (BST)

I don't really like "tidal flow" neither, but wiki states it very clear, that this is british english. I also would prefer "reversible" for this. Concerning your idea with the unified system: "lanes=forward|forward|reversible|backward|backward" wouldn't be consistent with the lanes tagging scheme, because you need a "base-key", i.e. something like "funnykey:lanes=x|y|z". Also you are mixing driving directions (forward/backward) with the kind of a lane (reversible). But this is still a good point! How about something like this:

 lane_kind:lanes=standard|reversible|standard
 direction:lanes=forward|forward|backward

The key lane_kind identifies the kind of lane and is not limited to any two-way/reversible/whateveryouliketocallthem lanes. And the direction key specifies the direction the lane goes. (In the above example the direction:lanes doesn't make much sense without condition, but I added it for better demonstration). --Imagic 07:59, 27 March 2012 (BST)

Number of lanes

While I assume that only a single 'median' and 'passing' lane makes sense (and only on non-oneway streets) which must be in the middle/centre of a carriageway (between forward and backward flow lanes), there might be several tidal_flow lanes (or even the complete carriageway can be reversible).

In addition to the option with the direction tag and the :lanes extension in your proposal, I would also allow a :both_way extension in addition to forward and backward: If more than one lane is of tidal_flow type, I would follow the current idea in the lanes tag with forward and backward and specific lanes:both_way=2.--Martinq 10:34, 26 March 2012 (BST)

Absolutely correct. I would also recommend lanes:both_ways=2 for this. In this proposal I want to introduce only the new key to prevent getting the proposal too big. But I will include this in the Further improvements section. --Imagic 12:25, 26 March 2012 (BST)