This paper summarizes the Crowdsensing-based Road Damage Detection Challenge (CRDDC), a Big Data Cup organized as a part of the IEEE International Conference on Big Data’2022. The Big Data Cup challenges involve a released dataset and a well-defined problem with clear evaluation metrics. The challenges run on a data competition platform that maintains a real-time online evaluation system for the participants. In the presented case, the data constitute 47,420 road images collected from India, Japan, the Czech Republic, Norway, the United States, and China to propose methods for automatically detecting road damages in these countries. More than 70 teams from 19 countries registered for this competition. The submitted solutions were evaluated using five leaderboards based on performance for unseen test images from the aforementioned six countries. This paper encapsulates the top 11 solutions proposed by these teams. The best-performing model utilizes ensemble learning based on YOLO and Faster-RCNN series models to yield an F1 score of 76% for test data combined from all 6 countries. The paper concludes with a comparison of current and past challenges and provides direction for the future.

Analyzing vehicle movement trajectories is essential for understanding urban mobility and traffic flow patterns. Obtaining a reliable estimate of vehicle trajectory is challenging as it requires the vehicle to be observed and re-identified at different locations and times. Recently, a scalable citywide traffic flow estimation method has been proposed utilizing moving cameras on vehicle dashboards. This study extends the recently proposed method for traffic flow estimation by using cameras mounted on multiple moving observers to reconstruct the trajectory of detected vehicles. We develop the CARLA ReID dataset, which includes more than 50,000 images taken from 85 cameras for over 700 different vehicle models, and train a re-identification network to identify the same vehicle by multiple observers. Utilizing our proposed methodology, we conduct extensive research to estimate trajectories of vehicles in a driving simulator CARLA and evaluate the accuracy of reconstructed trajectories using Symmetrized Segment-Path Distance (SSPD) and Hausdorff Distance metrics. Our proposed method achieves a mean error of 5.13 meters evaluated using the SSPD metric for ten driving experiments in CARLA. Findings from this study will provide valuable insights for conducting traffic flow research in a simulation environment, which is otherwise challenging and costly in practice.

Analysis of traffic fl ow pa rameters is ne cessary for Intelligent Transportation Systems (ITS) and autonomous driving research. Deep learning-based vehicle detection techniques have been widely used in reconstructing traffic fl ow parameters from video images. This research proposes a novel cross-sectional traffic fl ow es timation al gorithm to re construct tr affic volume from moving camera videos. We develop a vehicle detection dataset with more than one million annotations of vehicles with orientation and train a YOLOv4 based object detection network. We leverage the accurate vehicle detection model in tracking and estimating the distance of detected vehicles using Simple Online and Realtime Tracking (SORT) and photogrammetry techniques. The estimated distances and forward bearing of the observing vehicle are then utilized to calculate the GPS position of detected vehicles and used in the algorithm to estimate cross-sectional traffic fl ow. We ut ilize th e pr oposed al gorithm to es timate the traffic flow of 580 OpenStreetMap (OSM) road links and achieve an average accuracy of 84.30% verified a gainst 1 1 t raffic police sensor data in Susono city in Japan. The proposed large-scale dataset and cross-sectional traffic flow estimation algorithm open new avenues for ITS and autonomous driving research.

In recent years, due to various factors, including population decline, aging, and the promotion of compact cities, the social and lifestyle changes significantly impact people’s daily travel behavior. Although existing survey data and mobile phone data can reveal these phenomena, only aggregate-level results can be open to the public from the viewpoint of personal privacy. On the other hand, the conventional four-step travel demand estimation approach and human mobility models are limited to the low degree of freedom models, and hard to estimate the ever-changing traffic flow and the inability to capture the continuous behavior of people. This study develops a deep reinforcement learning-based agent model to tackle this problem and simulate the intercity people flow in the metropolitan area.

Human mobility datasets collected from various sources are indispensable for analyzing, predicting, and solving emerging urbanization and population issues. However, such datasets are only available to the public after aggregation and anonymous processing. In recent years, agent-based modeling approaches have addressed this problem by reproducing synthetic human mobility data through simulation. However, the development of such agent models typically requires a large amount of personal location histories as training data for parameter learning, leading to cost and privacy concerns. To overcome this disadvantage, we attempted to explore optimal parameters using a particle filter to alleviate the strict requirement of the data. We tested our method in a local city in Japan using aggregated real-time observation data collected from mobile phone service companies. The results show that the proposed model can achieve satisfactory accuracy using low-resolution data and can therefore be easily used by local governments for municipal applications.

This paper summarizes the Global Road Damage Detection Challenge (GRDDC), a Big Data Cup organized as a part of the IEEE International Conference on Big Data’2020. The Big Data Cup challenges involve a released dataset and a well-defined problem with clear evaluation metrics. The challenges run on a data competition platform that maintains a leaderboard for the participants. In the presented case, the data constitute 26336 road images collected from India, Japan, and the Czech Republic to propose methods for automatically detecting road damages in these countries. In total, 121 teams from several countries registered for this competition. The submitted solutions were evaluated using two datasets test1 and test2, comprising 2,631 and 2,664 images. This paper encapsulates the top 12 solutions proposed by these teams. The best performing model utilizes YOLO-based ensemble learning to yield an F1 score of 0.67 on test1 and 0.66 on test2. The paper concludes with a review of the facets that worked well for the presented challenge and those that could be improved in future challenges.

Railway disturbances occur every day and train rescheduling is conducted by human experts. Approaches for automating rescheduling have been widely studied (e.g., heuristic approach and mixed integer problem-based approach). However, extant research is still inadequate for employing the approach in practical application in terms of size, run-time, and solution accuracy. In this research, we simulate train dispatching using graph theory and propose a reinforcement learning method (i.e., Deep Q-Network (DQN)) for rescheduling. We also show experimental results of this algorithm. DQN presented positive results for over 50% of test cases, and its train rescheduling decreased approximately 20% of passengers' dissatisfaction in a certain case. It can be expected that applying a DQN approach to real-world scale cases by will improve methods to handle larger-scale networks.

In recent years, there has been remarkable development in unmanned aerial vehicle UAVs); certain companies are trying to use the UAV to deliver goods also. Therefore, it is predicted that many such objects will fly over the city, in the near future.

Real-time estimation of human mobility following a massive disaster will play a crucial role in disaster relief. Because human mobility in massive disasters is quite different from their usual mobility, real-time human location data is necessary for precise estimation. Due to privacy concerns, real-time data is anonymized and a popular form of anonymization is population distribution. In this paper, we aim to estimate human mobility following an unprecedented disaster using such population distribution data. To overcome technical obstacles including high dimensionality, we propose novel particle filter by devising proposal distribution. Our proposal distribution provides states considering both prediction model and acquired observation. Therefore, particles maintain high likelihood. In the experiments, our methods realized more accurate estimation than the baselines, and its estimated mobility was consistent with the survey researches. The computational cost is significantly low enough for real-time operations. The GPS data collected on the day of the Great East Japan Earthquake is used for the evaluation.