If you read the Lonely Planet or chat to people then the Ruta 40 is like the Route 66 of the US. ALthough I didn’t travel its length I did take in a vast portion of it. If ever asked what it was liek I say well it was good for the first hour, after the tenth it got a bit boring.
Don’t get me wrong the plateaux section across semi-dessert is amazing, as you really experience the curve of the earth, as the mountains sprout from the nowhere, and slowly grow and grow. However this experience does get a little old after a while, although it should also be noted that the road is generally straight, which when you have a van that struggles with going in a straight line, due to years of being hammer on dirt tracks, then the concentration require to go straight becomes exponentially more tiresome hour by hour.
There are some great roadsigns though!