Why not?  It just depends on the tags given by OSM.  You can restrict everything in osm2po.  For example: If a street restricts vehicles over 7 tons, there must be a tag for it.  If so, just compare the following example with the default config:

    wtr.flagList = 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