Well, you are now considerd illegal, join the crowd , be sure to keep that trailer under 9900 though. You will need to reregister, that will effect your truck insurance, might effect zoning laws if you take truck/trailer home, it never ends. Reg US DOT guidelines, the pattern I believe is that many states adopt them, but it is not mandatory, and the reason is someone from another state enters PA and gets busted and says how is he supposed to know the laws of PA ( guess he never heard ignorance is not defense line), so we are rapidly in the US approaching a single state status anyway, with a national ID/DL card not for behind because of all the warnings from homeland security to keep the bad guys out
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
, be sure to keep that trailer under 9900 though. You will need to reregister, that will effect your truck insurance, might effect zoning laws if you take truck/trailer home, it never ends. 
