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

Andy Robinson (blackadder-lists) ajrlists at googlemail.com
Tue Mar 31 23:43:36 BST 2009


Roger Slevin [mailto:roger at slevin.plus.com] wrote:
>Sent: 31 March 2009 11:20 PM
>To: 'Andy Robinson (blackadder-lists)'; 'Brian Prangle'; Talk-gb-
>westmidlands at openstreetmap.org; talk-transit at openstreetmap.org; 'Thomas
>Wood'
>Subject: RE: [Talk-transit] [Talk-gb-westmidlands] Naptan alignment
>
>Andy
>
>"Custom and Practice" stops - that is stops which are not physically marked
>- are a common feature in many parts of the country ... less so within
>Metropolitan areas than in rural ones.  And many are not "signed in one
>direction to represent both directions" - they are without any sign.  These
>unmarked stops are stop type CUS in NaPTAN.  I appreciate that their
>representation on a map might be conceptually challenging ... but they are
>essential points as far as bus passengers are concerned!

I have no problem representing them on a map and indeed the whole concept is
fine. Our challenge is one of verification. We essentially only put data in
OSM that is physically there on the ground. However at least these stops
have the "CUS" tag so it should be possible to verify that busses stop at
the location and the evidence on the ground might then be the pile of fag
ends in the gutter ;-)

Cheers

Andy

>
>Roger
>
>
>-----Original Message-----
>From: talk-transit-bounces at openstreetmap.org
>[mailto:talk-transit-bounces at openstreetmap.org] On Behalf Of Andy Robinson
>(blackadder-lists)
>Sent: 31 March 2009 23:11
>To: 'Brian Prangle'; Talk-gb-westmidlands at openstreetmap.org;
>talk-transit at openstreetmap.org; 'Thomas Wood'
>Subject: Re: [Talk-transit] [Talk-gb-westmidlands] Naptan alignment
>
>Using http://sautter.com/map I did a comparison of the precisely positioned
>stops I mapped this morning in the Aldridge area. Assuming Google has the
>locations the same as the NaPTAN data then I would say about one in 5
>NaPTAN
>stops has something wrong with the location. Mostly a stop is displaced
>along the street. These errors are as much as 30m.
>
>One interesting question relates to stops on the ground that exist only on
>one side of the street but state they also pickup/drop on the opposite side
>of the street. The NapTan data contains two stops when on the ground there
>is only one physical (pole or shelter). In general the NaPTAN data appears
>to show the stops staggered on either side of the street when in practice
>passengers are going to wait opposite the bus stop sign/shelter. At the
>moment I'm mapping these with one node and an opposite=yes tag on them.
>There is no way to map the stop on the opposite side as it doesn't
>physically exist. So what to do about the NaPTAN data in this case.
>
>Cheers
>
>Andy
>
>
>>-----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
>>
>>Thomas
>>
>>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.
>>
>>Regards
>>
>>Brian
>
>
>
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