The invitations would be much the same for the two roads. They would both encourage the reader to come and shuffle in the freshly fallen leaves - "leaves no step had trodden black." They would both be able to mention the beauty of the trees on either side and the glorious fall colors - "a yellow wood."
One road would be able to mark itself as being different by explaining that it was not as worn down as the other. Its grass was not trampled and flattened because there had not been as many walkers on it - "it was grassy and wanted wear." The other road could make a counter-claim that it was the more attractive choice because it was well-traveled, perhaps suggesting that it might be easy to get lost on the other, "the one less traveled by."