whyWhy not? it It just depends on the tags given by OSM. You You can restrict everything in osm2po. One For example: If a street restricts vehicles over 7 tons, there must be a tag for it. If If so, just compare the following example with the default config:
wtr.flaglistflagList = truck
wtr.finalMask = truck
wtr.tag.highway.motorway = 1, 11, 80, truck
... etc.
# just an example, don't know if such a tag exist in OSM
wtr.deny.tons.7 = truck