[1][2][3] Brazilian federal road names are composed of the ISO 3166 code "BR", a dash and three numbers.
The first digit in the number determines which of the five categories the National Road System divides it into.
BR-0X0 – start at the DF-001 in the Federal District and head towards the extremes of the country.
Radial highways are identified by the first digit "0", and the other two vary between 10 and 90, always in multiples of ten, each one heading in a different direction clockwise from the DF-001.
The direction of the distance starts from the DF-001, with the kilometre zero of each state being at the point of the highway closest to the federal capital.