[Tagging] Bridges and layers

[Dave F.]

  On 27/07/2010 00:28, Nathan Edgars II wrote:
> On Mon, Jul 26, 2010 at 8:45 AM, Dave F.<davefox at madasafish.com>  wrote:
>>   On 26/07/2010 13:35, Nathan Edgars II wrote:
>>> On Mon, Jul 26, 2010 at 8:28 AM, Dave F.<davefox at madasafish.com>   wrote:
>>>> Layer is used purely as an aid to the renderer to distinguish where two
>>>> or
>>>> more ways *cross* each other:
>>> Not quite purely - it gives nonredundant spatial information when a
>>> bridge goes over another. Not that this has anything to do with the
>>> layer_change proposal.
>> "nonredundant spatial information"
>>
>> What's that when it's at home?
> Information about the relationship of two physical objects to each
> other that isn't otherwise in the data.
>
> In other words, if you have two bridge=yes ways crossing without an
> intersection node, that tells you nothing about which one is the
> higher bridge. layer=* adds that information.

That's what I meant. Maybe I should have said 'crosses over'

Cheers
Dave F.