Judaism teaches that mourners should not show excessive grief and should try to avoid deifying the deceased. To this end, cemetery visitation should not be too frequent. Some authorities have said that the first time a mourner can return to the grave is after Shloshim, while others say a mourner may visit the grave at the conclusion of Shiva.
It is Traditional that when one attends a burial, visiting the graves of others who are in that cemetery is not done. Not visiting other graves is done out of respect to the person who is being buried, as well as to the person previously interred. Exceptions to this rule would be if the Burial attendees have come from a far distance, or to make another trip to the cemetery would be an undue hardship.