[Talk-GB] Bristol - a quick (and surprising?) statistic...

[Dave F.]

  On 02/08/2010 22:15, Richard Moss wrote:
>
>
>   On 23 July 2010, Tim François wrote:
> ...
> More info here: http://wiki.openstreetmap.org/wiki/User:Tiiiim#Bristol_-_Missing_Roads
> Perhaps the figure won't be surprising to many, but I thought it was pretty large! Is this representative of other similar sized cities/towns? (I know OSL isn't 'perfect', but its better than nothing....)
>
> ...
>
> I was shocked - here in Cambridgeshire, we thought we were getting close to 100% , particularly in the City and South Cambs, so I've had a look at my own village to try and understand what's going on.
>
> On the Royal Mail list of postcodes for the village, there are 46 streets, and in OSL, 10 of them are wrong - i.e. 78% correct, which is a bit worse than the 82.98% figure for South Cambridgeshire given at http://www.itoworld.com/product/data/osm_analysis/
>
> This is a list of the 10 that are wrong:
>
> Name in OSL		Name on OSM			Comment
>
> Chapman's Way	Chapmans Way		2 road name signs, both say Chapmans: OSM correct
> Hill Road		Mill Road			Mill Road is correct
> Unwin's Lane	Unwins Lane			2 road name signs say Unwins and 1 says Unwin's
> High Street		High Street (Over)	Useful distinction from nearby High Streets in
> 							Swavesey and Willingham, especially when these names
> 							appear in the like of www.cyclestreets.net . I'm not
> 							going to change what has been put on OSM
> Station Road	Station Road (Over)	ditto
> The Old Wood Yard	The Old Timber Yard	Whoops - my mistake. Careless adding of a new development.
> 							Sign says The Old Woodyard (all one word) so both wrong!
> 							I will correct
> Whines Lane		Whine's Lane		There are 2 road name signs. One of each
> The Doles		The Doles (East)		) OSM reflects signs on the ground. OSL agrees with the
> The Doles		The Doles (West)		) Royal Mail street list.
> Randalls Lane	Randall's Lane		Street sign says Randall's, as OSM
>
> (apologies if the formatting comes out wrong)
>
> In reality, there's only one error in OSM, and 45/46 is 97.8%. I don't want to get into a debate about apostrophes!

Oh go on, let's start another flaming war!   :)


To check, are the OSM names corroborative with the Royal Mail list?


> You could then note that there are various farm tracks outside the village which have names in OSL, missing on OSM and not in the Royal Mail postcode list: Long Lane, Ouse Fen Road or Bank, Long Holme Drove, Long Drove. There is no evidence for these names on the ground.

Personally, I would have no problem adding these to OSM.
I think OSL is more accurate than the RM.
Just because there's no sign on the ground it doesn't mean its nameless.

I take data from OS as evidence that there is a name for a road/track etc.

There are some who appear to treat the new data from the OS with extreme 
caution, even scepticism & are unwilling to add it.

I think it's a welcome addition & adds quality to the project.

A good caveat for those that are uncertain is to add the source tag 
stating that it came form the OS.


> Some have been added to OSM from local knowledge: Chain Road, Gravel Bridge Road. Then we are perhaps at 47/52 = 90.4%
>
> So I am heartened.  Tim's analysis is very useful in pointing out areas for attention, but the reality is not as bad as the figures suggest.

In you neck of the woods you'd be correct, but in Bristol there appears 
to be (almost) whole estates that don't even have the roads mapped.

Maybe for the reasons I suggested earlier.

I've tried to do my bit for the 'completeness' by adding a few green 
areas such as parks & golf courses etc.


Cheers
Dave F.