In Frost's poem, "The Road Not Taken," all we know from the narrator is that his having chosen the less traveled road has "made all the difference" (line 20). Whether this is a positive or a negative choice as applied to any particular individual is a matter of opinion. Bear in mind that no matter which the narrator had chosen, it would have "made all the difference" (line 20).
Which is positive and which is negative depends, I would say, on the kind of personality one has. A person who is risk-averse is likely to be happier in the end following a more traveled road. A person who is risk-seeking is likely to be happier following the less-traveled road. This is because the roads are a metaphor for our paths through life. At many junctures, we decide to do what most people do, to follow a path where most people have gone before, or to follow a path that is a bit different, one that is more likely to bring about atypical results. To apply this to the lives of most people I know, for example, one graduates from high school, goes to college, gets a job, gets married, and has children. However, some I know decided not to go to college but to go travel through Europe for ten years or join the Peace Corps. A few went to New York and became starving artists. My brother spent a few years on the road as a musician and dancer. For him, the road was a great choice. The less-traveled road can lead to great adventures and it can also lead to some very hard times.
Think about what kind of person you are. To decide whether this is a positive or negative choice means viewing the choice from your own perspective, since all the narrator tells us is that it made a difference, which is meaningless in a way, since if he had been presented with five different paths to follow, the choice of any would have made a difference.