Iowa DOT had developed a suite of crash mapping applications over the last 2 decades, and decided to update and consolidate those tools into a single modern web-based GIS platform. Since the various tools were used by a variety of users and agencies across the State of Iowa, the new application was to have multiple levels of functionality, allowing the application to be tailored to the needs and capabilities of a broad spectrum of users. Since the application used very large data sets, it was also critical to build the application and model the data for maximum performance.

Great Arc designed and developed a web-based mapping application that displays multiple years of traffic accident data for the entire State of Iowa. The application supports hundreds of users in local, regional, and state agencies, as well as the general public. Users may filter crashes by geographic location as well as by any of a multitude of attributes. Maps are rendered using the ESRI JavaScript API for ArcGIS Server. Great Arc also developed REST services using ASP.NET Web API that communicate with the source Oracle database to provide data to the client application. Users can view project information, overview maps, and charts depicting selected crash data characteristics. The application also includes a custom report builder, powerful search and filtering capabilities, a full suite of navigation and drawing tools, heat mapping, “stacks” – which is a simulated 3-D view of multiple crashes at locations, and the ability to download and export maps and tabular data.

One of the technical challenges we faced during this project was the requirement to display all traffic incidents for the entire state, over 500,000 points. Leveraging existing ESRI frameworks, Great Arc developed a custom point rendering map service to deliver high-performance, dynamically filtered map layers in under 2 seconds.

To develop the application, we built a replicated environment in our office that matches that of the client, including the same version Oracle database. We modeled and built all application configuration data, as well as loaded (and partially altered) client data, in Oracle.