In accordance with the advancement of technological development, access to all types of digital data is becoming increasingly important. Various problems are commonly faced when obtaining digital data from existing maps. These include errors caused by the imperfection of the digitizing device, deformations in paper maps, errors in matching the data along the edges of adjacent paper maps, and systematic errors caused by the operator. Although the data obtained from photogrammetric methods are affected by pointing errors by the operator and errors occurring when analog photos are scanned, these errors are independent of the deformations that occur in paper maps. This study compared the raster maps produced from aerial photos with the data acquired from digitized vector maps. The statistical distributions of the discrepancies obtained as a result of this comparison were analyzed. The data from the scanned map and photogrammetric map were found to be consistent with each other, but the scanned map and newly produced map were not consistent with each other. DOI: 10.1061/(ASCE)SU.1943-5428.0000040. (C) 2011 American Society of Civil Engineers.