[Tagging] source:maxspeed vs. maxspeed:type

[Kytömaa Lauri]

>And usually we
>use the key source for how we collect the data, but not the key
>source:maxspeed 

Realistically, to know that there is a speed limit 
sign, or that there isn't one (i.e. =sign 
vs. =XX:urban), one has had to visit the place,
so source:maxspeed key effectively says the data
is from a survey.

Some may have used suitable photos or videos showing
the sign, or lack of a sign, but still somebody was there
to record the surroundings - that is, something akin
to source="survey by friend"

-- 
Alv