# [Tagging] tagging of one-way cycle lanes

Martin Koppenhoefer dieterdreist at gmail.com
Fri May 11 12:56:50 UTC 2018

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sent from a phone

On 11. May 2018, at 14:25, <osm.tagging at thorsten.engler.id.au> <osm.tagging at thorsten.engler.id.au> wrote:

>> If 3 vehicles drove side by side (which is the
>> typical situation there, not counting the psv lane), which one would be "outside" the lanes?
>
> The middle one clearly, it's half way in each of the official lanes.

sounds logical, but it is strange: assume 2 cars driving on the right side of the road (as required by the traffic code) side by side, now a third car overtakes, which is completely legal if there is sufficient room, regardless of lanes. Why should this put the law abiding driver of the middle car in a suspicious condition? Now imagine this is not one car, but lots.

>
>> while I still agree, following this concept would mean to count
>> lanes based on situations somewhere else, not?
>
> In the absence of any signs that would indicate such a change, it depends on the width of the road.

>
> In that case, if there is a clear point where the width of the road changes, that's the split point.
>

+1

> If the chance is gradual, take the midway point.

this IMHO is not compatible with the verifiability criterion

>
> If there is no noticeable change in the width of the road, assume the number of lanes in traffic flow direction remains constant up to the point where it clearly is indicated by road markings to be different.
>
> Assuming you have high enough resolution imagery, use JOSM and the "lane and road attributes" mapstyle, then specify your lane widths in detail using width:lanes at the points where the lanes are clearly marked.
>
> Adjust the geometry of the way to try and fit it into the available road surface along its way. Then work outwards in both directions from the points where you know the lane count for sure based on road markings, you will clearly see if there are places where you need to increase or decrease the lane widths.
>
> If you need to decrease the land width below about 2.5m to make it fit, that's a strong indication that you have too many lanes from that point on. If you have to increase the land width much beyond 3-3.5m, AND further down the road are more lanes than you currently have, it's probably time to increase the lane count.

Seems workable, but the result would still be questionable WRT verifiability. At this point it seems most sane to omit the lanes tagging in the absence of road markings and indicate just a width (if only they hadnâ€™t set up this psv lane recently it would be cleaner)

cheers,
Martin
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