I am a citizen of Rome at the height of the Roman Empire, one day I decide I would like to see this glorious Roman Empire for myself. Could I do it? Where could I travel? Where couldn't I?
Heres a few links that might interest you from similar questions:
http://www.reddit.com/r/AskHistorians/comments/1kw7oc/identity_verification_in_ancient_times/
(This post below is about a leader, not a normal citizen)
http://www.reddit.com/r/AskHistorians/comments/1td4hx/how_did_roman_emperors_travel_how_were_they/