I understand that the red, yellow and green lines give a general idea of how bad traffic is on a road, but do they have any specific meaning, like red equals a 40-minute wait at a toll bridge? a. According to the Google Maps site, the colored lines representing traffic conditions on major highways refer to the speed at which one can travel on that road.
The oldest form of writing known to man is Cuneiform used in Mesopatamia.
An additional possibility is the undeciphered Rongorongo script of Easter Island. It is debated whether this is true writing, and if it is, whether it is another case of cultural diffusion of writing. The oldest example is from 1851, 139 years after their first contact with Europeans.