[Talk-transit] [Talk-gb-westmidlands] Naptan alignment

Andy Robinson (blackadder-lists) ajrlists at googlemail.com
Tue Mar 31 13:23:07 BST 2009

I've already started correcting data like this. I too have noted that some
stops are not correctly positioned in relation to the road they are on.
Where we only have a single trace along a road they could be correct but the
ones I looked at last night where we have plenty of traces (main road) were
in some cases either too far back or too close to the centreline of the
road. I also fond some possible referencing errors for bus stop pairs on
either side of the road but need to resurvey as a double check.

As of my mapping session this morning I'm taking my bike right up to the
stop and taking the photo from directly under the sign. That should help see
what sort of positional errors exist in the data. The only problem is that
I'm mapping Walsall and so need more imported data before I'll know ;-)



>-----Original Message-----
>From: talk-gb-westmidlands-bounces at openstreetmap.org [mailto:talk-gb-
>westmidlands-bounces at openstreetmap.org] On Behalf Of Brian Prangle
>Sent: 31 March 2009 9:46 AM
>To: Talk-gb-westmidlands at openstreetmap.org; talk-transit at openstreetmap.org;
>Thomas Wood
>Subject: [Talk-gb-westmidlands] Naptan alignment
>I've also looked at Google maps and their alignment is off too in exactly
>the same way ours is in areas I know well and have surveyed, so I guess
>it's down to the NaPTAN data. There are examples where I know the bus stops
>are in a row along the street (Corporation Street  and Acocks Green Village
>for example) but NapTAN has one or two skewed from the line by several
>metres.  Currently I favour correcting the NapTAN data  to what we know on
>the ground, but until a consensus emerges I'm laying off the urge to
>correct it.

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