Mobile systems for adaptive road safety and time-relevant modal shift

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School of Science | Doctoral thesis (article-based) | Defence date: 2020-12-18
Degree programme
68 + app. 72
Aalto University publication series DOCTORAL DISSERTATIONS, 219/2020
Mobile networks have brought the opportunity of using smartphone data to investigate the challenges of road safety and travel mode choice for sustainable urban mobility. This thesis adopts the mobile cloud computing (MCC) approach and uses smartphone data to address these two challenges. Road safety influences the mode choice between private cars and low-carbon transportation that usually involves walking and cycling. In this regard, pedestrian collision avoidance is crucial for both conventional and autonomous vehicles. As dedicated 802.11p-based device-to-device communication is not readily available on smartphones, collision warning systems could use a designated mobile app for indirect vehicle-to-pedestrian (V2P) communication and centrally perform the collision prediction on cloud servers. Vehicular safety applications require high-frequency beaconing to achieve adequate locational and temporal precisions. In these situations, the power consumption of beaconing can create a bottleneck due to the limited capacity of smartphone batteries. In addition, cellular network capacity and cloud computation resources could be limiting factors that require their own city-scale assessments. To address these issues, this thesis investigates the practicality of smartphone-based V2P collision warning systems by means of model and prototype evaluations. We need to analyze extent and variations of battery consumption under different traffic conditions, assuming a situation-adaptive rate control is used for communication. We also need to examine the network and computation load of the system and compare them against the capacity and cost of available infrastructures. Regarding mode choices, a modal shift from cars to lower-carbon alternatives results in changes in travel-times, emissions, and physically-active distances. An increased travel-time can be a barrier against the realization of modal shifts, due to limited daily time-budgets of people. Despite significant development in data collection technologies, there is a limited focus on the decision-support perspective and developing useful computational frameworks for a time-relevant modal shift analysis. This thesis aims at developing a prototype of an MCC-based framework that uses smartphone data to show the extent of potential changes with modal shifts while taking into account travel-time changes. Such a framework would involve extracting observed door-to-door trips from smartphone data, computing realistic low-carbon alternatives to compare with those observed trips, and finally estimating the potential changes. Moreover, due to the nature of urban travel patterns, any proposed method should be evaluated in realistic scenarios and consider spatiotemporal variations. This thesis seeks to acquire realistic trace data of target urban regions and use it to evaluate the proposed frameworks. While the numerical outcomes could differ between cities, such experimental evaluations should demonstrate the overall practicality and usefulness of the methods.
Supervising professor
Supervisor: Professor Antti Ylä-Jääski, Antti, Prof., Aalto University, Department of Computer Science, Finland; Mladenovic, Milos, Prof., Aalto University, Department of Built Environment, Finland
Thesis advisor
Nurminen, Jukka K., Prof., University of Helsinki, Finland
Kosonen, Iisakki, Dr., Aalto University, Finland
pedestrian safety, mobile networks, smartphone data, travel mode choice, low-carbon transportation
Other note
  • [Publication 1]: Bagheri, M., Nurminen, J. K., Siekkinen, M., “Cellular-based Vehicle to Pedestrian (V2P) Adaptive Communication for Collision Avoidance,” in Proceedings of the 3rd International Conference on Connected Vehicles and Expo (ICCVE), pp. 450-456, IEEE, 2014.
    Full text in Acris/Aaltodoc:
    DOI: 10.1109/ICCVE.2014.7297588 View at publisher
  • [Publication 2]: Bagheri, M., Siekkinen, M., Nurminen, J. K., “Cloud-Based Pedestrian Road-Safety with Situation-Adaptive Energy-Efficient Communication,” IEEE Intelligent Transportation Systems Magazine (IEEE ITS) vol. 8, no. 3, pp. 45–62, 2016.
    Full text in Acris/Aaltodoc:
    DOI: 10.1109/MITS.2016.2573338 View at publisher
  • [Publication 3]: Bagheri, M., Mladenovic, M.N., Kosonen, I., Nurminen, J.K., Roncoli, C., Ylä-Jääski, A. “A Computational Framework for Revealing Competitive Travel Times with Low-Carbon Modes Based on Smartphone Data Collection.” Journal of Advanced Transportation, vol. 2020, Article ID 4693750, 20 pages, 2020.
    Full text in Acris/Aaltodoc:
    DOI: 10.1155/2020/4693750 View at publisher
  • [Publication 4]: Bagheri, M., Mladenovic, M. N., Kosonen, I., & Nurminen, J. K., ”Analysis of Potential Shift to Low-Carbon Urban Travel Modes: A Computational Framework Based on High-Resolution Smartphone Data.” Sustainability, 12, Article no. 15, 5901, 24 pages, 2020.
    Full text in Acris/Aaltodoc:
    DOI: 10.3390/su12155901 View at publisher