Road lighting luminaires are divided into 3 groups according to CIE; The classification of luminaires according to CIE

* Maximum luminous intensity can be 1000 cd.

I80 : the maximum luminous intensity value for the angle of g = 80o with respect to the vertical axis in C=0o and C=20o planes (in terms of cd/1000 lm), I90 : the maximum luminous intensity value for the angle of g = 90o angle with respect to the vertical axis in C=0o and C=20o planes (in terms of cd/1000 lm), gmax.: The angular value at which the maximum luminous intensity (Imax) occurs.