The Iowa Department of Transportation (IaDOT) maintains city maps for the 947 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 IaDOT files are maintained with Bentley's MicroStation software and use Bentley's "DGN" as the native file format. Information regarding MicroStation can be found at Bentley's site. If you choose to download a city file in the "DGN" or AutoCAD "DWG" formats, you will need software that reads those formats. Bentley offers a "DGN" and "DWG" viewer called Bentley View which can be downloaded here. Adobe PDF files require Adobe Reader available here.

MicroStation utilizes a leveling scheme for the storage of different classes of map information. The IaDOT leveling scheme for a downloaded MicroStation file is available here. Additional information contained in a downloaded file was determined to be unecessary for a majority of the online viewing users and was eliminated to decrease the time needed to display a file. The city map metadata is available by clicking here. The map projection metadata is available by clicking here.

The IaDOT maintains county maps for the 99 counties in Iowa. The maps available were originally created in 1987 from USGS digital line graph data. Since then, the maps have been updated and enhanced using information from road plans, aerial photography, USGS 7.5 minute quadrangle maps, USGS digital raster graphics, GPS data, as well as other sources.

The IaDOT files are maintained with Bentley's MicroStation software and use Bentley's "DGN" as the native file format. Information regarding MicroStation can be found at Bentley's site. If you choose to download a county file in the "DGN" or AutoCAD "DWG" formats, you will need software that reads those formats. Bentley offers a "DGN" and "DWG" viewer called Bentley View which can be downloaded here. Adobe PDF files requires Adobe Reader available here.

MicroStation utilizes a leveling scheme for the storage of different classes of map information. The IaDOT leveling scheme for a downloaded county file is available here. The county map metadata is available by clicking here. The map projection metadata is available by clicking here.