MetroViz: Visual Analysis of Public Transportation Data
This tool addresses the need for better analysis of public transportation data for schedule optimization and resource allocation, but it is incremental as it applies existing visualization techniques to a specific domain.
The authors tackled the problem of analyzing public transportation service quality by developing MetroViz, a visualization tool that integrates map, route, and calendar views to explore ridership and adherence data, which was evaluated through usability tests with researchers and students using three years of bus transit data from Blacksburg, Virginia.
Understanding the quality and usage of public transportation resources is important for schedule optimization and resource allocation. Ridership and adherence are the two main dimensions for evaluating the quality of service. Using Automatic Vehicle Location (AVL), Automatic Passenger Count (APC), and Global Positioning System (GPS) data, ridership data and adherence data of public transportation can be collected. In this paper, we discuss the development of a visualization tool for exploring public transportation data. We introduce "map view" and "route view" to help users locate stops in the context of geography and route information. To visualize ridership and adherence information over several years, we introduce "calendar view" - a miniaturized calendar that provides an overview of data where users can interactively select specific days to explore individual trips and stops ("trip subview" and "stop subview"). MetroViz was evaluated via a series of usability tests that included researchers from the Center for Advanced Transportation Technology (CATT) and students from the University of Maryland - College Park in which test participants used the tool to explore three years of bus transit data from Blacksburg, Virginia.