An electrical wiring structure and a computer system for designing the electrical wiring structure. The electrical wiring structure includes a wire pair. The wire pair includes a first wire and a second wire. The second wire is slated for being tri-stated. The wire pair has a same-direction switching probability .phi..sub.SD per clock cycle that is no less than a pre-selected minimum same-direction switching probability .phi..sub.SD,MIN or has an opposite-direction switching probability .phi..sub.OD per clock cycle that is no less than a pre-selected minimum opposite-direction switching probability .phi..sub.OD,MIN. The first wire and the second wire satisfies at least one mathematical relationship involving L.sub.COMMON and W.sub.SPACING, where W.sub.SPACING is defined as a spacing between the first wire and the second wire, and L.sub.COMMON is defined as a common run length of the first wire and the second wire.