Symbols...

Water, cleaning and washing

Water is the one of the most needed things for humans, or for any animal to live. The reason that humans can live on earth is because of water, other planets in our solar system do not have life because there is no water. So when the man has to purify the water using the cloth it shows the only thing that stops the world from depletion is corrupted.

The mountain
The sea
The colour grey (gray American spelling) Ash

Ash is a sign of fire which has died out and left the scraps unable to burn, on the road it is everywhere, the scraps of humanity which the fire can't quite destroy but it useless, dirty and unneeded... Depressing
The boy also plays with the ash with his truck before the roar rats come, this could be showing the world is so empty that you can look at a small part, or a larger part but they will both seem the same.


Fire

Fire has always been essential for human's to survive. Since the stone ages it is well known that cave men were to make fires from sparks. So when they go back to making them to keep warm (something for we don't use fires directly anymore) it shows humanity going backwards.
Also in a lot of books, animals have been portrayed to be afraid of fire, this is the only thing in the dead world they belong that separates them from the beasts.

Sight/sightlessness

The man has lost all sight for the future, all he can see is where the road is leading next. He never plans for anything only on getting to the coast, but even when they get there, there is no planning on where to go next, only making camp.

Seeds
Music/musical instruments Animal imagery


Religious imagery

The Road talks of God having left the world, but God's word being spoken through the boy. , these are two quite opposing ideas, but could represent the boy being the son of God (like Jesus) this is also symbolised by when his father died he waited 3 days before coming out the woods, quite like Jesus arose from the dead on the third day. Then he meets a man who could help him survive. His father would never let him do this (as he did not trust other people on the road) so like the curtain being ripped in the temple, a metaphorical curtain has been ripped so now the boy can go live with the remaining good guys... I accept that this might be considered very wooly...

The Coca Cola can

The Coca Cola can could in this represent humanity as it is "good" but very few and far between. It is also a place the father gives something to the boy and he enjoys it, it is one of the only times that he ever brings good news (the cola in this being the good news) to the boy.