Noise arising from line-to-line coupling is a major problem for deep submicron design, and present technology trends are causing an increase in this type of noise. Common current methods to decrease coupling noise include shielding and buffering, both of which can increase overall power dissipation. An alternative method is spacing, which has the added benefit of improving the manufacturability (i.e.defect insensitivity) of the design. This paper explores the issue of coupling noise reduction, and proposes performance metrics that can be used by the designer to determine which of the alternative methods is best suited for a specific interconnect configuration.