High-Accuracy Geometric Highway Model Derived from Multi-Track, Messy GPS Data

GPS provides longitude, latitude, and elevation points and is already integrated into some highway data collection processes at the Kansas Department of Transportation. For instance, GPS tracks have been systematically collected on the 11,500 mile Kansas state highway system since 1997 as part of two separate data collection activities: videolog and pavement management. While not the primary purpose of the data collection activities, over 11 million GPS points have been collected to date. These individual geodetic points became the basis for a high-accuracy geometric highway model and for a high-quality base map for GIS purposes. Methods to process this data were developed and applied to the entire database of GPS points, resulting in a geometric model of the state highway system. In turn this geometric model can now be used as the basis for other applications. One of the first applications was the assessment of sub-standard stopping sight distance. The principles and mechanics of the processing methods that combine multi-year, multi-run GPS data into highly accurate spatial models are reviewed and summarized.