In UNSBR, the states of India are numbered from 1 to 29. (From South to North) Then we divided Kerala into 14 districts, and gave alphabets as codes starting from the southern end district, Thiruvanathapuram to the north end district Kasaragod. Thus Thiruvananthapuram is labeled ‘A’ as the first district from the south end. Similarly, Kasaragod is given ‘N’ being the 14th. Accordingly, Kannur district is labeled 'M'. The routes are numbered on zonal basis. For this Kannur district has been divided into four zones. The zones are divided on the basis of convenience and the availability of the buses. Various names of colors are assigned to these zones viz. Red zone, Green zone , Blue zone & Yellow zone.