As you may know, IRIS supports the tracking of geographic information system (GIS) locations for road features located at specific points such as signs, culverts, and bridges by allowing you to enter the global positioning system (GPS) coordinates for the road feature. Doing so can help you visualize the location of road features on a map, as well as perform some rudimentary analysis.
What you may not be aware of though, is with the right road base map, you can actually use GIS for all of the road features in IRIS! If your county’s GIS department has mapped your road centerlines with an appropriate linear referencing system (LRS), GIS programs such as ESRI ArcGIS can easily place those features on the map for you. The LRS defines the line work for the road, as well as the starting and ending milepost. It can then take the data from IRIS, and based on road number and milepost(s), determine where along the centerline the feature should be located.
The biggest advantage of this approach is it allows you to use the data you already have on hand, rather than having to spend additional time in the field collecting new GIS data.
Furthermore, as your road centerline mapping and/or your feature mileposts improve, your GIS locations will inherently improve as well. In addition, an LRS can help you perform more advanced analysis requiring distances between points on a road, which cannot be done with the GPS point method.
If you are interested in making the most of GIS and IRIS, please contact us at [email protected], and we can help you get started creating an IRIS-compatible linear referencing system.