[OSM-newbies] Road Maximum speed in UK units

[Ed Loach]

Bill wrote:

> when explicit units are supported, implicit units are wrong and
> dangerous, so use the units.

For a long time maxspeed was km/h only, with no units specified.
Through common usage, number with an optional unit (usually mph) has
been documented on the wiki (and perhaps because there were so many
different values for the conversion from mph to km/h that no-one
seemed to agree). Unless you want to retag the metric world's
already tagged ways, you have to allow a default unit (for when none
is specified). 

Of course if you do want to update all the km/h (with no units)
tags, agree with anyone who wants to help you whether you want to
use km/h, kph, kmph, etc and go ahead. You can race those people who
are updating all the oneway=true (an older accepted value) to
oneway=yes (standardised value, which one day will allow renders to
simplify their stylesheets, apparently)...

Ed