[Talk-GB] maxspeed field - what units should we use. etc

[Ed Loach]

> FWIW highway code conversions are:
> 20mph = 32
> 30mph = 48
> 40mph = 64
> 50mph = 80
> 60mph = 96
> 70mph = 112

Ah - which differs from what is posted on roads out of ports:
http://wiki.openstreetmap.org/wiki/Image:MaxSpeedConversionHarwich.jpg
(60mph = 95km/h, 70mph=110km/h, and it looks like I didn't get the previous sign which gives all the other common speed limits in steps of 15km/h starting I think with 30mph=45km/h)

Ed