[Talk-transit] NaPTAN in Nottingham & Notts: early use of the data

Jerry Clough - OSM sk53_osm at yahoo.co.uk
Thu Sep 24 20:40:48 BST 2009

I've now had a few days to contemplate the Nottingham & Notts NaPTAN data, so I thought I'd write 
quick summary of what I've been doing. Feedback and suggestions all most welcome.

	* Use the data to name noname roads. I managed to resolve quite a number of unnamed road issues thanks to the detail in the data. Using ITO's OSM Mapper I've saved an image of the changes made based on this information: http://wiki.openstreetmap.org/wiki/Image:Nottingham_NaPTAN_derived_road_names.jpg
	* Add major missing roads. Alignment of bus-stops have also allowed a much smaller number of roads to be added. Being able to add these roads, which of course will all need surveying, makes planning future surveys using only OSM sourced data much easier. I use main roads for survey area boundaries, but they are also very useful for estimating survey complexity (which even OSGB 1:25000 aren't much use).
	* I've merged very few bus stops as yet, just a few which I've happened to pass. Overall impression is that the stops in the city of Nottingham are accurately located. Some of the differences may be between boarding point and the flag location (I always try and take this). All stops which I encounter which are not already on OSM, where my GPS reading is close will just be tagged as verified, and source=naptan_import;survey. 

	* Details like indicator & shelter will not always be available immediately a bus stop is verified. Today I passed a whole slew which I waypointed, but I'd run out of convenient bits of paper and space on the dictaphone. I'd rather revisit these than try and guess which had shelters/indicators.
	* Quite a few stops don't have indicators, but the infrastructure is being installed. I propose to tag these electronic_indicator=installation.
	* One stop does not appear to exist on the ground: Charlbury Road ( http://osm.org/go/eu8ZC@@J9-- ). A bus does seem to run along this road, but I suspect it is a hail-and-ride sector.
	* Trams. I have been re-tagging tram stops to railway=tram_stop and changing name to reflect signage at the stop (usually this means removing "Tram Stop") from the name. As there is a stop for each direction, incorporating the NaPTAN stuff for the NET-1 (Nottingham Tram) will take quite a lot of work. Most of this needs to be done: the single node on the track did not allow adequate representation of pedestrian access, particularly to island platforms. I am proceeding to rework tram stops in Basford which are not on a road. I am just creating two ways adjacent to the tram stop. One tram stop, Cinderhill, has two stop points, but it has a single platform for up and down direction trams, and a single track. This seems wrong, but I am open to correction: particularly if the data model enforces such a difference.

	* Stop Points. Many stops belong to multiple stop points (presumably part of a hierarchical arrangement), but some of these seem to have little utility. For instance, stops BA82 and BA05 located at the junction of Vernon and Nottingham Roads, belong to stop areas 339GBA09, 339GBA10 and 339GBA24. The latter seems far too far away and is probably an error, but there seem to be large numbers of overlapping stop areas, which to me as a passenger do not seem logical. I'll look into this more once OPNV has rendered the data.Thanks to all who made this possible.

Jerry Clough

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