01517611

Component

Previous research has reported on the need to implement quality control programs for ITS data to address critical issues such as suspicious or erroneous data, nature and extent of missing data, and accuracy and comparability of ITS data to similar data sources. This paper summarizes the work completed to address quality control and completeness issues associated with a very large archived ITS data set composed of some 3.4 billion 20-second lane detector data records from San Antonio’s TransGuide. The paper includes a description of the quality control tests utilized, the results of the analysis conducted, and a discussion of ITS data completeness issues. The researchers also utilized GIS to prepare maps showing the spatial trends in the distribution of quality control flags. These maps showed cases where the spatial distribution was roughly uniform, but also cases where there were significant exceptions. An evaluation of temporal variations in the distribution of quality control flags showed that, in most cases, the highest concentration of flagged records occurred at night, when there was relatively little traffic and, consequently, there was a higher chance for time intervals without vehicles or for isolated detector readings producing abnormal data. Finally, the researchers evaluated the data completeness both at the aggregate level (by server) and a more detailed individual detector level. This paper not only provides a revised set of quality-control tests, it also describes an innovative spatial and temporal analysis of data quality for two-year worth of data. While the analysis described in this paper uses data from one jurisdiction (San Antonio, Texas), the methodology is sufficiently generic to enable implementation at other traffic management centers.

This paper was sponsored by TRB committee ABJ50 Information Systems and Technology.

01503729

14-1318

English

23p

2014

Transportation Research Board 93rd Annual Meeting

Digital/other

Figures; References; Tables

Data banks; Data quality; Geographic information systems; Intelligent transportation systems; Methodology; Tests; Traffic distribution

TransGuide (Program : San Antonio, Texas)

Data and Information Technology; Highways; I72: Traffic and Transport Planning

Transportation Research Board Annual Meeting 2014 Paper #14-1318

TRIS, TRB, ATRI

Jan 27 2014 2:30PM