A Conflation Methodology for Two GIS Roadway Networks and Its Application in Performance Measurements

Abstract

In the current environment, in which private sector organizations play an ever increasing role in providing traffic data and tend to report data based on proprietary maps, it is inevitable that public sector agencies will want to adapt the spatial data and to use it in their legacy systems. Thus, for the same transportation infrastructures, a variety of GIS roadway datasets based on different highway reference location systems and segmentations are developed. This paper presents a method and a workflow to conflate such networks. The matching process usually involves projecting one network onto another. The first step in this process is to match the typically proprietary private sector network with the public sector legacy network. Different public and private entities may use different location referencing systems for analysis and reporting of data. So, in most cases, it is necessary to transform the spatial data from one location referencing system to another. Geographic information systems (GIS) offer a powerful tool for this purpose. GIS uses standard referencing systems to locate the features in a transportation network. This study proposes a methodology that takes advantage of GIS capabilities in the projection of transportation networks. A workflow is introduced based on the proposed methodology. A tool is created to perform the projection in the ESRI ArcGIS environment. Sanity checks and some reporting options are presented. Results are reported on projecting a subset of the Highway Performance Measurement System (HPMS) used by Maryland State Highway Administration onto the Traffic Message Channel (TMC) network in Maryland.