[OSM-talk] How to use lanes= for two way single track roads?

[Andy Robinson (blackadder)]

Paul Hurley wrote:
>Sent: 12 March 2008 10:10 PM
>To: talk at openstreetmap.org
>Subject: Re: [OSM-talk] How to use lanes= for two way single track roads?
>
>Alex Mauer wrote:
>
>	DavidD wrote:
>
>
>		According to map features the value for the lanes key should
>be.
>
>		"Number of travel lanes in each (or only permitted)
direction"
>
>		I've been tagging to this definition.
>
>		"Number of travel lanes on the way"
>
>		This makes more sense to me because you can tag two way
single
>lane
>		roads with lanes = 1. The map features definition on the
other
>hand
>		doesn't give an obvious way to tag these roads. lanes = 0.5
>perhaps.
>
>
>
>
>	It also runs into trouble with 3- and 5-lane roads.  Tagging the
>total
>	number of lanes makes a lot more sense to me. (per carriageway if
>	applicable, since each should be mapped separately)
>
>
>
>I have recently posted a similar question to the newbies list.  There are
>two roads I've mapped recently where a short section has a width
>restriction meaning cars can only pass in one direction at a time, and I
>don't know how to map it.  If lanes is the total lanes for a way this would
>work, but how does osmarender render this ?
>

I believe the renderers currently ignore the lanes attribute and draw ways
(those with the same highway tag) in the same width, regardless of the
number of lanes.

For your single lane passing restrictions I think you have two options,
either split the way into logical sections and tag with lanes=2 and lanes=1
etc as appropriately, or if the restriction is just that, ie a set of
bollards or whatever restricting traffic to one lane then you could add an
appropriate tag to nodes where each restriction exists. In either case
though it's not something we are likely to see rendered any time soon, but
like other traffic calming features its useful to know this information for
other uses. Personally I haven't been bothering to go to this level of
detail on a particular way, favouring the simpler approach of adding a
traffic_calming=true tag to the whole way.

Cheers

Andy

>Thanks
>
>Paul.
>
>
>--
>Paul Hurley	http://www.paulhurley.co.uk/
>The knack of flying is learning how to throw yourself at the ground and
>miss.
>    Hitchhikers Guide to the Galaxy