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Why does not Mapnik render highway lanes? There is a great inconsistency about what highway=trunk means... sometimes it is used for single lane roads (mostly in United Kingdom) and sometimes it is used for say 2nd grade motorways (multiple lanes, continental western Europe for instance). If we rendered highway lanes, this inconsistency would disappear.

asked 12 Mar '14, 21:32

Kozuch's gravatar image

accept rate: 8%

closed 14 Mar '14, 13:04

Richard's gravatar image

Richard ♦

The question has been closed for the following reason "This is a feature request phrased as a question, not a request for help" by Richard 14 Mar '14, 13:04

I think you should talk first with the UK community and check with them why "trunk" seems inconsistent. It is possible that locally someone made a mistake about the "trunk" class.

The "highway=trunk" is also used differently depending on the country. Here is a table showing the international equivalence of the "highway" tags.

You can contact the UK community through this dedicated mailing list (needs subscription).

Here, in short, I can only provide some generality : the "highway" class reflects its importance in the road grid. Usually the amount of lanes is related to this importance (more traffic=more lanes). We can expect that the amount of lanes is greater in motorways than in residential streets. You might find some exceptions but then, it should be carefully verified and see if it is not simply a mapping mistake.
The rendering styles currently use the "highway" class to set the colour and line width. It's not using the tag "lanes=" or "width=", excepted perhaps for the very high zoom levels where these attributs can really impact the resulting images.

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answered 14 Mar '14, 11:01

Pieren's gravatar image

accept rate: 15%

Lanes=<value> should only effect the width of the road based on their default lane width. And if possible you can add width=<value> and width:lanes:[forward/backwards]=<value>(“|” divider if needed)<value> for overriding the lanes default width. The lanes or the better option of lanes in conjunction with the width, should be the only thing rendered. This would fix a lot of visual understanding of roads in open areas or visually and statistically knowing if you can use the roads in tight spaces.

(10 Jan '18, 20:30) Mxdanger

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question asked: 12 Mar '14, 21:32

question was seen: 4,244 times

last updated: 10 Jan '18, 20:37

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum