The Iowa DOT maintains city maps for the 945 incorporated cities in Iowa. The maps available were originally created in 1987 from manually drafted city base maps. Since then, the maps have been updated and enhanced using information from road plans, aerial photography, United States Geological Survey (USGS) 7.5 minute quadrangle maps, USGS digital raster graphics, global positioning system (GPS) data, as well as other sources.
The Iowa DOT files are maintained with Bentley's® MicroStation software and use Bentley's® DGN as the native file format. Visit the
Bentley® website for information regarding MicroStation. Special software is required to download a city file in the DGN or AutoCAD DWG formats. Bentley® has a DGN and DWG viewer available,
Bentley® View. Adobe® PDF files require
Adobe® Reader®.
MicroStation utilizes a leveling scheme for the storage of different classes of map information.
View the Iowa DOT leveling scheme for a downloaded MicroStation file. Additional information contained in a downloaded file was determined to be unnecessary for a majority of the online viewing users and was eliminated to decrease the time needed to display a file. View the
city map metadata or the
map projection metadata.