Date of Award
Doctor of Philosophy
Civil, Construction, and Environmental Engineering
Presently, there is an expanding interest among transportation agencies and state Departments of Transportation to consider augmenting traffic data collection with probe-based services, such as INRIX. The objective is to decrease the cost of deploying and maintaining sensors and increase the coverage under constrained budgets. This dissertation documents a study evaluating the opportunities and challenges of using INRIX data in Midwest. The objective of this study is threefold: (1) quantitative analysis of probe data characteristics: coverage, speed bias, and congestion detection precision (2) improving probe based congestion performance metrics accuracy by using change point detection, and (3) assessing the impact of game day schedule and opponents on travel patterns and route choice.
The first study utilizes real-time and historical traffic data which are collected through two different data sources; INRIX and Wavetronix. The INRIX probe data stream is compared to a benchmarked Wavetronix sensor data source in order to explain some of the challenges and opportunities associated with using wide area probe data. In the following, INRIX performance is thoroughly evaluated in three major criteria: coverage and penetration, speed bias, congestion detection precision.
The second study focuses on the number of congested events and congested hour as two important performance measures. To improve the accuracy and reliability of performance measures, this study addresses a big issue in calculating performance measures by comparing Wavetronix against INRIX. We examine the very traditional and common method of congestion detection and congested hour calculation which utilized a fixed-threshold and we show how unreliable and erroneous that method can be. After that, a novel traffic congestion identification method is proposed in this paper and in the following the number of congested events and congested hour are computed as two performance measures.
After evaluating the accuracy and reliability of INRIX probe data in chapter 2 and 3, the purpose of the last study in chapter 4 is to assess the impacts of game day on travel pattern and route choice behaviors using INRIX, the accurate and reliable data source. It is shown that the impacts vary depending on the schedule and also the opponents. Also, novel methods are proposed for hotspot detection and prediction.
Overall, this dissertation evaluates probe-sourced streaming data from INRIX, to study its characteristics as a data source, challenges and opportunities associated with using wide area probe data, and finally make use of INRIX as a reliable data source for travel behavior analysis.
Ahsani, Vesal, "Big data driven assessment of probe-sourced data" (2019). Graduate Theses and Dissertations. 16952.