[Tagging] Dispute prevention: meaning of lanes tag

Ilpo Järvinen ilpo.jarvinen at helsinki.fi
Mon Apr 23 12:31:57 BST 2012

On Sun, 22 Apr 2012, martinq wrote:

> > I've had a look for uk guidance as the uk's ordnance survey was
> > mentioned, and a lot of older uk advice appears based around a now
> > historic view that 'cars = saloon cars' and were 1.8m or less. If cars
> > were assumed to be 1.8m wide then implied OS figure of 4m for two lanes
> > makes sense.
> I am not sure we should base the lanes tag value on typical car width.
> IMO the lanes tag should *not* be another kind of estimate for the width.

However, trying to decouple lanes fully from width also decouples you from 
reality where they are in some kind of relation (albeit somewhat loose 
one here and there).

> A further problem is the definition: For example the "euro track" has a
> maximum allowed width of 2.55m without mirrors (refrigerated ones even 2.60m).
> This would be as fair as basis as a "average" car in UK or a UK guide. And in
> US or India we may find another situation again.

...There's one law detail here somewhat interesting in this context. It's 
illegal to park/stop here when there's yellow don't-cross-line and you'd 
block the available room so so that less than 3m remains available 
(IMHO it's not far that this 3m width could be thought to be kind of 
minimum "lane" width which is not, at least directly, bound to anything in 
the realms of "typical/maximum allowed width").

> In residential areas/streets I omit lanes if they are not marked. Parking
> allowance and parking cars on the street/carriageway make the situation very
> complicated. Look here:
> http://bit.ly/I2hna7
> While the carriageway in this example is more than 6m wide and allows two
> trucks to pass, you also see parking cars in this street (I don't know the
> German law, but they might be allowed to do that). What would you do now? And
> if the parking allowance is time limited? For me lanes is simply not
> applicable here.
> --> I would tag the parking information with parking:lane, width, but not
> lanes.

But then it would well be possible to have even the lanes=2 marked for 
that street (at least around here), so essentially one of the marked 
lanes would be quite much blocked by the legal parking (it would be 
illegal to park on both sides so close to each other that the others 
could not get through anymore).

--> so I don't see how it would be any less problem by not applying lanes 
at all if parking is allowed but on the same time marking lanes only if 
marked to the street because both would be true!?!

In general I agree with you here though that the parking makes it 
much more complicated.

> > After reading through these emails I'm beginning to think the
> > lanes=1.5 would less confusing for narrow two lane roads.
> -1
> 1.5 makes no sense. If we can agree that a lane is a "strip, which is wide
> enough for one moving line of motor vehicles other than motor cycles" (from
> the Vienna Convention of Road Signs, used as basis for local law in many
> countries all over the world) -- then either one line of vehicles can move --
> or two.

"wide enough", isn't that about the same as "has enough width"?

> --> For me this lanes=1.5 is a clear indication for an attempt to turn the
> lanes tag into a rough width-estimate. I think the width tag is the better
> tag for width-estimates.

No, I don't agree it's a width estimate. ...I think it's more an attempt 
to put something more meaningful to the lanes tag than 1 or 2. That is, 
clearly such street is not plain lanes=1 because it's possible to traffic 
both directions at the same time, nor is it lanes=2 in the sense that you 
cannot just pass incoming car without interference like you could on "a 
real lanes=2" road (or at least most people wouldn't, it's legal though 
up to maxspeed like it would be to pass a traffic_calming=choker too but 
usually people won't try that :-)).


More information about the Tagging mailing list