[Tagging] Dispute prevention: meaning of lanes tag

[John F. Eldredge]

Andrew Errington <a.errington at lancaster.ac.uk> wrote:

> On Mon, April 23, 2012 03:57, Martin Vonwald wrote:
> > 2012/4/22 Jason Cunningham <jamicuosm at googlemail.com>:
> >
> >> After reading through these emails I'm beginning to think the
> lanes=1.5
> >>  would less confusing for narrow two lane roads.
> >
> > The problem with lanes=1.5 stays: data consumers might not be able
> to
> > handle this correctly.
> >
> > What we need right now is a recommendation how to handle this
> "narrow
> > road"-problem, without using a tag, that might cause more problems
> than it
> > solves. What is the problem with the following: __________
> > If a two-way road is so narrow, that passing cars have to slow down,
> > then besides lanes=2 either 1) measure the width and set the tag
> > accordingly (preferable, but usually much too difficult) or 2)
> simply use
> > est_width=4 (or width together with source:width). __________
> >
> >
> > Instead of one problematic tag (lanes=1.5) we would use well
> established
> > tags.
> 
> 
> I agree.
> 
> I think lanes=* should record the total number of marked lanes (i.e.
> road
> markings must be present to indicate the lanes).  lanes=1.5 is
> subjective,
> and anything subjective should be avoided.  Instead, record width=*
> (estimated or actual) then the onus of interpretation falls on the
> user,
> not the mapper.
> 
> Best wishes,
> 
> Andrew
> 

I agree that having the actual width helps.  I once encountered a country road that had a center line painted, so that, officially, it was two lanes wide.  Unfortunately, the total road width was only about three meters, so only bicycles or motorcycles would have been able to use it in both directions simultaneously.  For anything four-wheeled, it was only one lane wide.

-- 
John F. Eldredge --  john at jfeldredge.com
"Reserve your right to think, for even to think wrongly is better than not to think at all." -- Hypatia of Alexandria