Do I always need a preposition when I say..
"I traveled (in) NY?"
Can I simply say, "I traveled NY"?
I'd say that there is a difference in meaning.
I travelled in New York (State) = I went here and there in NY State.
I travelled New York (State) = I covered most of the state. I journeyed widely.
The transitive (or surface-transitive, if seen as prepositional deletions?) constructions "travel(l)ed the world", "travelled the continent" and certainly "travelled the state" are not uncommon. I think it's the 'journeyed widely throughout', 'covered the length and breadth of' sense. Probably, substituting individual states would not be seen as unacceptable. Anything smaller, like a region, wouldn't sound too good (*/?I travelled the Brecon Beacons) (though the preposition chosen here might well be 'around').
The use, or not, of the preposition depends on your intended sense. If you want to convey that you traversed NY, no preposition is needed. If you want to convey that you traveled inside NY, the preposition is needed.
From The Free Dictionary:
- a. To go from one place to another, as on a trip; journey.
To pass or journey over or through; traverse