Baltic States Tripoints

There is a remote possibility that I will be able to visit the Baltic states
Lithuania, Latvia and Estonia for a few days near the end of next month. I
have enjoyed the pictures and narrative at Jan Krogh's site
http://geosite.jankrogh.com/ that covers this area and I wonder if anyone
can shed any light on which, if any, of the tripoints (EELVRU, BYLTLV,
BYLTPL and LTPLRU) can be visited without having to make special
arrangements beforehand with border authorities.
 
Thanks
 
Hugh