[OSM-talk] lanes

[Philip Homburg]

In your letter dated Mon, 13 Oct 2008 11:00:39 +0100 you wrote:
>On Sun, Oct 12, 2008 at 9:48 AM, Gervase Markham <gerv-gmane at gerv.net> wrote:
>> LeedsTracker wrote:
>>> As Shaun says, the unresolved issue of lane handed-ness seems to be
>>> blocking this lane issue.
>>
>> This is anothe occasion where a generic :left/:right proposal would be
>> useful...
>
>Yeah, not so much. Given that London Bridge has a cycle lane, a
>separate bus lane (also for cyclists) and a normal lane (for
>everything else, and buses, and cyclists) on one side of a
>dual-carriageway then your simplistic generic system won't work. 

How to specify the order of various lanes is independent of the left right
order. For example, you could say

lane_order=left_to_right
lane1=cycleway
lane2=primary;access=no;psv=yes;bicycle=yes
lane3=primary

etc.

>Also,
>I challenge you to come up with the user interface that doesn't
>confuse the contributor when you say "which side of the road is the
>cycle lane on" and they say "the left" but they need to mark it as
>cycleway:right because they are facing the "wrong" way on a two-way
>street.

That easy, you just get the user to click on the side of the road where
the lane should appear, and the user interface renders it there.

>The main objection to "left" and "right" is that most roads don't have
>an intrinsic direction, certainly not one visible on the ground. At
>least oneway roads have a fairly obvious direction when you're out
>mapping.

Even for the current (JOSM) style tagging: just adopt a convention where in
roads that are not oneway the arrows are drawn bottom to top, and left to
right. Then in most case people will get it right. And by the time those
lanes are actually rendered (preferably also in the editor), people will
realize their mistakes quickly enough.