Graphical analysis of roadway sufficiency parameters for improved asset management

Abstract

The Iowa DOT currently employs a rating methodology for prioritizing highway improvement needs. The rating procedure combines separate scores based on roadway structure, safety, and service categories into a final score referred to as the sufficiency rating. This rating is used to objectively compare one segment of the highway system to all others for construction or major rehabilitation needs. To perform analysis on sufficiency scores, decision-makers require the entire array of data and categories involved in calculating the sufficiency rating. The objective of this study was to assemble the information necessary for analysis and provide rapid, easily understood access to these data using geographic information system (GIS) software. A customized GIS interface was developed specifically to access sufficiency information.

This interface allows decision-makers to view a number of graphical display tools displaying information such as sufficiency score and specific roadway characteristics. The contributions these GIS tools have to sufficiency score analysis are discussed. The benefits include time saving and improved understanding of what impacts particular roadway conditions may be having on a roadway's final sufficiency rating. The results of the research indicate that using the described GIS sufficiency reporting and analysis tools can convey understandable information to decision-makers in a faster, more-detailed manner than traditional tabular reporting schemes and paper maps. Using GIS tools, planners are able to better interpret sufficiency-rating scores to allow better management of assets.