[Tagging] highway=motorway and motorroad (implies)

[Simone Saviolo]

In Italy, access to motorways is forbidden to any vehicle not able to
reach 80 km/h on a level floor, and motorbikes and motorcycles under
250cc are excluded too. The motorway must be a dual carriageway (which
implies oneway=yes) with at least two lanes per carriageway. There may
be sections with deviations, closed lanes, etc. because of work in
progress and construction sites, but these are usually temporary.

IMO, if the law defines motorways to have certain features, these
should be implied.

Regards,

Simone