[Tagging] convention for multiple maxspeed values

[Richard Welty]

some highways have split max speed values, different
for passenger cars and trucks. i don't see any provision
for tagging this on the map features page.

are there any existing proposals for dealing with this?

if there aren't, i'd like to suggest something like

maxspeed:hgv=50 mph
maxspeed:goods=50 mph

thanks,
    richard