[Tagging] maxspeed=signals

[Martin Vonwald]

>> I would prefer to allow (not require) an additional unit information (mph,
>> km/h), simply to encourage data consumers to deal with them as they are
>> usually added by users.
>> On the other hand no data consumer can be sure about a (global) default
>> unit if there's no unit given.
>
> I thought it was assumed to be metric unless specified otherwise.

Correct: http://wiki.openstreetmap.org/wiki/Units

If all data consumers respect that is a different story ;-)