Many land use-transportation planning proposals aim to create neighborhoods with higher levels of neighborhood accessibility (NA). This article focuses on how such features are operationalized for purposes of research and/or regional modeling. The first section reviews specific variables classified by three basic tenets of NA: density, land use framework, and streets/design. The second section describes challenges in measuring NA to provide a better understanding of how such challenges shape research efforts and applications. The final section creates an NA index that is applied to the Central Puget Sound metropolitan area. The index uses detailed measures of density, land use mix, and street patterns and makes at least five contributions for urban form research.