One of the most contested areas within the taxi industry is based on the availability and servicing of specific routes, particularly those deemed to be busiest. To address this issue and bring clarity and structure to taxi operators and passengers on these routes, in 1996, SIYAZI developed a colour-coded system.

The requirements for the colour coding are that it should be easy to understand but still contain all the information that the passengers, other operators, and law enforcers need to see immediately and be able to determine on which road or route a vehicle is supposed to operate. The aim was that the colour-coding would also assist tourists and visitors, enabling them to use combi-taxis to travel to various destinations in the area.

The system has two elements, namely the background that indicates the origin and the colour of the line, which indicates the destination or the route followed.