A back-country unpaved road. They are found in various states of repair; the good ones are graded and covered in gravel. They are referred to as such because they most often run North-South and East-West as if on a grid.
Known to Saskatchewanians.
The boys got in the truck and went for a booze cruise on the grid roads outside of town.
The farmer took the grid road to get from her home quarter to town.