Iowa Department of Transportation Office of Transportation Data GIS / CAD Integration From GIS data to CAD graphics - Iowa DOT's workflow utilizing GeoMedia and MicroStation to develop map products. Mark Hansen and Nick Meurer
GIS / CAD Integration MicroStation/IGDS since 1986 Roadway database since the 1970 s They were completely separate work flows until 1995 when we started to attribute the roadways in MicroStation with a database linkage. We now have our Geographic Information Management System (GIMS) which stores data in an Oracle 10g spatial database. Fall of 2006 we re-digitized the roadway centerlines, structure locations, rail crossing locations, section lines (township lines, county & state boundaries), and city corporate limits to 2 meter accuracy from aerial photography.
Geographic Information Management System Attributed Roadway Centerlines Business Data
New Geographic Information Management System
Accuracy Improvement GIMS Before GIMS After LRS
Map Projection Information Custom Lambert Conformal Conic projection In 1997, the Iowa DOT moved from NAD27 to NAD83 datum which allowed for future integration of the current CAD files with more accurate GIS and GPS technology. All of our CAD maps and GIS data are drawn or digitized in the same projection, therefore we are able to fit any combination of state, county or city maps together with our GIS line work and have everything line up correctly. This also allows our CAD maps to be easily exported to a KML file and be brought into a Google Earth environment effortlessly.
State of Iowa
Interstate 1,047.391 miles
Primary - 8,353.093 miles
Municipal - 14,468.724 miles
Secondary 90,038.345 miles (P & I 550.399 miles) 1,047 8,353 14,469 90,038 + 550 114,457
City Corporate Limits for 947 Cities
24,598 Structures
5,195 Railroad Crossings
All (300,000+ records maintained)
Old Map Production Method Manual manipulation of certain cartographic features (bridges, secondary road banding, etc,) In the past, over 20 different queries were ran against our GIMS database in a custom MicroStation environment each year. Each query would generate a different DGN file for each of the 99 counties in Iowa by different surface type, jurisdiction, other variables, etc. These different DGN files were then merged together to create one complete county file. Example EDG script:
New Map Production Method Various queries are ran in GeoMedia and then exported out to MicroStation DGN via the Export to Design File command to generate: 1. Statewide DGN by surface type 2. Statewide DGN for all bridges 3. Statewide DGN for all corporation limits 4. Statewide DGN for all railroad crossings 5. Mileposts: location and value 6. Traffic Counts 7. Section Lines 8. County Boundaries 9. Various other Cartographic features (MicroStation clip shapes, road banding, etc.) cont
New Map Production Method cont.. Seed file is attached during the export process to embed projection information into the DGNs and maintain IDOT s spatial component. Custom cell and font libraries are attached, depending on the map to be produced, to the give user a wide variety of symbology/text options. The newly generated design files are used to update older maps to current year data or are used as a basemap to build a complete new product. Use of XML file during export to DGN from GeoMedia to maintain accurate design standards throughout the office.
GIS to CAD Workflow Demo
Types of Products Produced State Map County H&T Map City Map Various Special Request Maps
Embedded Font PDF Searchable text Color Dramatic file size decrease City, County, & State Transportation Map
Layered PDF Turn layers Off/On inside the PDF Named Levels Reference Files Ability to print only what is displayed in the PDF Ability to add drawings, markups and engineering links County H&T and Special Request maps
Closing Remarks Our GIS/CAD integration has automated what were once time consuming processes of updating our maps and have saved countless hours and resources. GIS/CAD integration has enabled us with quick turn around time for special request maps. Ex. Bridge maps after MN Bridge collapse Future projects will include Rail centerlines and updated Statewide hydrology, both digitized from aerial photography.
Contact Us Find contact information. We d be happy to answer your questions. Download PDF maps (State, County, City and Traffic), Digital Maps (DGNs, DWGs, and shapefiles) and Transportation Data. Order paper maps