Basically, Frost's writing is very much colloquial but at the same time very suggestive. And, The Road not Taken is not an exception for this but one of his finest works.
First of all, it is a Lyrical poem and we find one of his personal experiences in the poem. In the poem, the poet has done the job very impressively through his verse that one can relate. Getting to the end, we notice that it becomes a generalized theme to us and not more being just a personal lyric. In a simple sentence, we may say that it's a metaphorical poem. One last thing, it is a poem with the rhyme scheme of ABAAB type.
Summary
At the beginning of the poem, we get to know the poet's encounter with a bifurcation. He was walking down a road and the road was now found to be a fork. Simply, that one road is now divided into two roads. He is saying that being (alone) one traveler he can go to only one path and not to travel both. So, he thought he should choose the road wisely. For this reason, he noticed the first path very consciously and looked down toward it as far as he could.
Thereafter, it came to the poet's mind, that perhaps the second one could be better for him. Then, he started to watch the second path. Then he found this one grassy and wanted wear- that means the majority of people didn't choose this one, so it was grassy. But, next thing came to his mind that perhaps all paths were looking similar.
Now, after thinking and analyzing two roads, he chooses the second road and leaves the first one for another day. But, at the next moment, he becomes pretty much sure that he could not go to the first road anymore. As one road leads to another and to another and so on, that's why it becomes next to impossible to go to that point.
In the last stanza, Frost is thinking about the future consequences of selecting the second path and leaving the first one. He is seeing himself as his future version who is sighing by thinking over that day's decision. The road which was different from the other one made all the difference in his life.
Analysis
As it belongs to the genre of metaphorical poems, it must be critically explained and has some inner meanings. And 'The Road not Taken' is a poem which easily meets the criteria of being a metaphorical poem.
In the poem, the poet is found confused about choosing the appropriate road between the two roads. Apparently, it seems an experience of the poet's own. But, Frost is not a poet who creates a poem only based on a simple meaning.
So, if we deeply focus on the poem, then it is not the dilemma of only the poet's own, rather it becomes a symbol of choosing the right decision of every common people.
Sometimes, we have to choose one between two decisions which we face throughout our life. And this dilemma comes to every person's life and we have to choose it sincerely. It can be the decision of taking arts or science stream after the exam of class 10th or it could be the choice of medical field or engineering or general stream. And, we have to choose one path or road for the future and leave the other one. Not only just selecting but also the right thing becomes necessary for our upcoming future. And it becomes one of the most vital and critical times of our life as every decision that was made by leads to the different outcomes as well as the destination.
One more thing, the poet, has beautifully described in the poem that sometimes all the roads seem almost the same. And, then it becomes very much difficult for us. At that time, we cannot make the decision very easily as we become very much confused.
Last but not least, the poet, is metaphorically giving the reference to his chosen decision. Perhaps, metaphorically he is trying to say about his decision, taking the field of literature which creates larger impacts in the literary world. And that's why we are discussing it.