[Talk-GB] The OSM UK map

David Woolley forums at david-woolley.me.uk
Wed Nov 15 13:44:37 UTC 2017

On 15/11/17 13:18, Adam Snape wrote:
> Interesting, but if your interpretation of the law regarding red/green 
> distinctions is correct, why do the majority of road road atlases on 
> sale and most maps (both open and proprietary) supplied by Ordnance 
> Survey maintain the red/green colouring?

OS certainly have thought about colour blindness, e.g. 
and <http://www.wired.co.uk/article/ordnance-survey-cvd-maps>.  My 
guess, though, is that paper maps are not legally a service, unlike web 
sites, so are immune from the legislation.  There probably also haven't 
been test cases.

> Incidentally, my father is red/green colour blind and can tell the 
> difference between the two shadesused in road atlases. He does however 

Varying the shade as well as the colour, is one way of making maps 
colour blind friendly.  My understanding, though, is that the degree of 
colour blindness varies, even within the predominant type found in UK 
males.  Also colour vision is affected by the yellowing of the eye with 
age, so something that works for one person, may not do so for another.

The Wired article, above, indicates that there were problems with 
non-traditional colours for roads, which were resolved by creating 
lightness/darkness contrasts.

> sometimes struggle with the picking out  the green dashed rights of way 
> on the OS 1:25K Explorer mapping.

Googling "colour blindness os maps" throws up a lot of potentially 
interesting material on the subject.

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