This project aims to enhance existing 2D-CAD utility maps that the Cadaster generates when receiving a request for subsurface information; a KLIC-melding. We aim to enrich these 2D maps by including 3D information (geometry, depth). Since this information is not documented widespread, we develop a ‘fuzzy 3D model’ that generates 3D utility information from multiple sources of information (e.g. estimated depth, depth according to standard design rules, and actually measured depth). We integrate the resulting 3D model in an Augmented Reality tool, e.g. Google Glass, to test how 3D fuzzy maps (in Dutch ‘3D-ongeveer’) meaningfully support utility construction and maintenance.

The number of urban subsurface utility reconstruction activities grows this decade as local utility owners need to renew their existing sewage, energy, and water networks. Simultaneously, SMART technologies – such as fiber optic glass, smart grids, energy convection – continue to be added to the underground, creating a subsurface puzzle of intersecting networks that need to be maintained and updated frequently. This requires civil engineers to use sophisticated systems to support design, engineering and (re)constructions of the urban subsurface. The worldwide registration standards and norms, however, use only schematic 2D CAD drawings (e.g. figure 1a). Some utilities are mapped by using their relative location (e.g. 10m from a house), rather than their actual location. Furthermore, official depth coordinates are largely unavailable. Consequently, existing maps are of limited use when locating utilities in the field; identifying design conflicts; and, planning construction work. Our observations in Dutch practice show that one main reason not to add 3D coordinates is that they are not ‘absolutely accurate’. Surprisingly, however, most practitioners do make well-founded estimates about utility locations by using heuristics, standards, and assumptions. Such information is valuable for generating a first version of a 3D map of Netherlands’ subsurface infrastructure: a fuzzy 3D utility map. Such a map would include various accuracy levels of 3D location information, and may significantly support design and construction.