[OSM-talk] Cycle Lanes

David Earl david at frankieandshadow.com
Mon Mar 31 16:28:45 BST 2008


I think Peter is spot on here.

David

On 31/03/2008 15:59, Peter Miller wrote:
> Can I suggest that the vehicle oneway=yes/no attribute should be able to
> take an additional value of 'reverse' to make all the tags independent of
> the direction of the way and avoid the need to reverse ways at all. I do
> agree that attributes should use prefix values of forwards/backwards and
> left/right and that editors should reverse these if the way is reversed.
> 
> Btw, this approach is used by GDF where a direction attribute is used which
> can take the values 'traffic is allowed in both directions', 'traffic is
> closed in the positive direction', 'traffic is closed in the negative
> direction' and 'traffic is closed in both directions' (9.3.6). I believe
> that this attribute in GDF can be used in conjunction with a vehicle class
> to create different rules for different types of vehicle (including
> pedestrians and cyclists).
> 
> With regard to the debate about separate tracks or a 'handed' attributes for
> the road I would suggest that there are times where either might be
> appropriate, but that it would be reasonably easy to create a separate track
> automatically from a 'handed attribute' if required (and would be much
> easier than the reverse transformation) so the handed approach should be
> preferred.
> 
> I also suggest that it will be easier for the renderer to encode parallel
> cycle lanes on cycle maps using the convention of colour coding the casing
> of the road if the handed approach is used. Currently there are a lot of
> problems with separate cycle tracks close to roads getting obscured by the
> road itself or indeed obscuring the road.
> 
> Personally I will continue to use handed attributes where the track is
> parallel to the road and where there is no barrier between the track and the
> road (other than some grass and a kerb).
> 
> Fyi, the Cycle Data Standard for the Department for Transport in the UK that
> I worked on in the autumn used the concept of an 'offset path' which had is
> own identity (and could therefore be used in relationships) but which
> borrowed its geometry from the main way to avoid all the problems of
> stitching the way into all the side streets and to allow 'casing colour'
> style maps to be created. I am requesting that they publish the standard so
> we can compare and contrast and will let you know when it becomes available.
> 
> 
> 
> 
> Regards,
> 
> 
> 
> Peter Miller
> 
> 
> 
> 
>> Message: 1
>> Date: Mon, 31 Mar 2008 11:41:26 +0000 (UTC)
>> From: David Dean <ddean at ieee.org>
>> Subject: Re: [OSM-talk] Cycle lanes
>> To: talk at openstreetmap.org
>> Message-ID: <loom.20080331T112301-897 at post.gmane.org>
>> Content-Type: text/plain; charset=us-ascii
>>
>> Martin Vidner <martin.osm <at> vidner.net> writes:
>>
>>> Make the prefixes "left:", "right:" special in the sense that when a
>>> way is reversed, they get swapped.
>>> So left:highway=bus_stop would become right:highway=bus_stop.
>>> (Uh, maybe this is awkward for the renderer implementation. Could be
>>> better to prefix the *value* instead: highway=left:bus_stop?)
>>
>> It seems to me that you could define the two sides of a way independent of
>> the
>> direction (if any) of the way. I'm just not sure what you would call the
>> two
>> sides.
>>
>> For example, lets start with "north" and "south". This would unambiguously
>> define the two sides for all ways that are not running directly (or close
>> to)
>> north-south. "East" and "west" would work for those of course, but we want
>> the
>> same name no matter what the angle of the road.
>>
>> Maybe you could use "clockwise" and "anticlockwise" to define the side of
>> that
>> portion of the road you would get if you rotated it in that direction.
>>
>> So what I am basically getting at is that you don't need to define the
>> side of
>> the road based on the way direction, as it can be defined by the compass
>> points,
>> I'm just not sure what the two labels would be. Maybe "north-or-east" and
>> "south-or-west" shortened to "noe" and "sow" could work if everything was
>> clearly defined on the wiki.
>>
>> - David
>>
> 
> 
> 
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