If you are on a deserted highway and you see no transportation vehicle at all, start walking.Look for a kilometre post. Yes, that yellow stone marker on the side of the road. For example, you see a kilometre post as in the picture, but the road is deserted, no tricycle, no vehicles, no people. How do you read the marker? KM 340 means you are 340 kilometers away from Luneta, Manila. D2 means the kilometre post is 2 kilometers away from the center of a town which name starts with a letter D.
It could be Daet in Camarines Norte or Damortis in La Union. If you are good in geography, you would guess that it’s Daet because Damortis is less that 300 kilometers from Luneta. Otherwise, you do not know.
But there is something else you can do: Face the road with the kilometre post on your left and start walking. In such orientation, you are walking towards Manila. If you face the road with the kilometre post on your right, it means you are walking away from Manila. Walk a kilometre and find the next kilometre post. If the figure is KM 339 it confirms that you are walking towards Manila. Read the next figures. If it says D3, it means you are walking away from the town center. You now have a choice to go back to reach the center of the town and get transport. It it says D1, you are lucky because you are walking towards the town center, and you could find help there.
source: FB post by Abdon M. Balde Jr.