text: Unfortunately you're right. OSM classification is mapped to official one and by official classification the road via Joniškis itself is of more importance. The only thing which could be done is to add traffic lights, crossings, speed limits and such on A12 in Joniškis and hope that routers will take that into account and find 210 road faster.
  BTW: MapQuest is routing via Joniškis bypass.