I’ve just started, and have mapped some of Alnwick in the North East UK
using JOSM, and am slowly getting the hang of it I think.
One question I can’t find a good answer to on the wiki or forum is how
to tag a road that has a single lane restriction, i.e. traffic can only
pass in one direction at a time. There’s one on a bridge to the north
of Stakeford which is governed by traffic lights and one in the middle
of Alnwick through a monument kind of arch thingy which is just goverend
by good behaviours (no, it doesn’t always work).
Obviously you can tag oneway, or a width restriction, but I don’t think
that is right. Anyone have any better ideas (or am I missing something ?)
Hmm just guessing here, but adding width=“1 car at a time” and oneway=no, then add the traffic lights to the map, and a big FIX_ME=“this street only carry one car at a time, don’t know how to model this”.
The thing is it really is an ordinary street just a bit different…
I just use lanes=1 to indicate the road is only one lane wide.
However Map features states,
"Number of travel lanes in each (or only permitted) direction "
I see it as
“The number of travel lanes on the way”.
I don’t know how you are susposed to tag single lane roads that are not one way using the map features definition. lanes=0.5 perhaps
we need “lane=single” for this, but there is no such tag yet.
lanes-1 seems correct, as there is only 1 ‘travel lane on the way’ but it’s direction alternates. so it’s lanes:1 oneway:no (oneway:no being default anyway)
For generally narrow roads, there are 2 lanes as there are 2 directions of travel, but due to the width these 2 lanes overlap, so lanes:1 is incorrect in this instance. lane:single is lane:1. A thin road can be defined by added width: and/or a tag which groups the thin roads into various sizes rather than going for the precision that width= requires.