In recent years, we have witnessed the emergence of the implementation and integration of significant working solutions in transportation, especially within the smart city concept. A lot of cities in Europe and around the world support this initiative of making their cities smarter for enhanced mobility and a sustainable environment. In this paper, we present a case study of Tartu city, where we developed and designed a daily real-time system for extracting and performing a modal split analysis. Our web-based platform relied on an optimization approach for calibrating our simulation in order to perform the analysis with the use of real data streams from IoT devices installed around the city. The results obtained from our system demonstrated acceptable performance versus the quality of the available data source. In addition, our platform provides downloadable OD matrices for each mode of mobility for the community.
2 September 2021 in IEEE Transactions on Intelligent Transportation Systems
The fast development of information and communication technologies has engendered a massive generation of mobile data with great potential for extracting mobility patterns and sensing urban dynamics. The data, itself, has unique characteristics depending on the technology and the network coverage design for different zones (urban-rural). Therefore, many research directions investigated the potential of such data to extract some important features of traffic information, such as travel time estimation, traffic flow, etc. From this perspective, our paper focuses on highlighting the advancements done during the last twenty years concerning the usage of mobile phone network data to estimate vehicles’ travel time in different geographical conditions. Furthermore, it discusses and covers the existing literature methods and the challenges they face due to the nature of the data, its quality, and its complexity. Finally, we reveal the main trends and directions for future work.
The emergence of smart cities is set to transform transportation systems by leveraging real‐time traffic data streams to monitor urban dynamics. This complements traditional microscopic simulation methods, offering a detailed digital portrayal of real‐time traffic conditions. A framework for near‐real‐time city‐scale traffic demand estimation and calibration is proposed. By utilising Internet of Things (IoT) sensors on select roads, the framework generates microscopic simulations in congested networks. The proposed calibration method builds upon the standard bi‐level optimization formulation. It presents a significant computational advantage over available methods by (i) formulating the optimization problem as a bounded variable quadratic programming, (ii) acquiring sequential optimization technique by splitting computations into short time frames while considering the dependency of the demand in successive time frames, (iii) performing parallel simulations for dynamic traffic assignment in corresponding time frames using the open source tool Simulation of Urban MObility (SUMO), and (iv) feeding traffic count data of each time frame as a stream to the model. The approach accommodates high‐dimensional real‐time applications without extensive prior traffic demand knowledge. Validation in synthetic networks and Tartu City case study showcases scalability, accuracy, and computational efficiency.
13 December 2017 in Discrete Mathematics, Algorithms and Applications