Some embodiments of the invention provide an integrated-circuit chip that has a design based on a wiring model that allows at least a particular wiring layer to have more than one preferred wiring directions. Other embodiments provide a method of manufacturing an integrated circuit ("IC") that has a plurality of wiring layers. The method specifies a layout of the IC by using a wiring model that specifies more than one preferred wiring direction for at least a region of a particular wiring layer. The method then uses the layout to fabricate the integrated circuit.