Abstract: The present embodiments relate generally to techniques for creating and/or modifying multi-layer buses in an IC design. According to some more particular aspects, embodiments relate to techniques for allowing an IC designer to efficiently transition a multi-layer bus section made of N wires and M layers to another multi-layer bus section made of N wires and any other M? layers. In some embodiments, the user describes, programmatically, one or several custom transitions called a custom transition procedure and saved in a human-readable text file that can also be read by a layout editor tool. By a command associated with the custom transition procedure that is exposed to the user in the layout editor tool, a multi-layer bus is automatically transitioned from a set of layers to another.