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: [email protected] [mailto:talk-gb- >[email protected]] On Behalf Of Brian Prangle >Sent: 31 March 2009 9:46 AM >To: [email protected]; [email protected]; >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 _______________________________________________ Talk-transit mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-transit
