Junji Urata

The University of Tokyo | Todai · Department of Civil Engineering

This paper focuses on sequential and forward-looking behavior in destination choices of full-day. We can model the forward-looking behavior in the activity chain using a β-scaled recursive logit model that can not calculate future utility if the number of destination candidates is too large. Our primary objective is to construct a practical approac...

Since the Great Hanshin-Awaji Earthquake, Japan has experienced numerous disasters. This study aims to review the research trends of reconstruction planning in Japan, focusing on architecture, urban planning, and civil engineering since 1995. We found that the number of reconstruction planning researches has significantly increased since 1995. Ther...

Ride-sourcing drivers spend a significant portion of their service time being idle, during which they can move freely to search for the next customer. Such customer-searching movements, while not being directly controlled by ride-sourcing platforms, impose great impacts on the service efficiency of ride-sourcing systems and thus need to be better u...

Relief supply distribution is a critical issue to mitigate the impacts of disasters. In Japan, two types of strategies, push-mode and pull-mode, are included in disaster management plan, for prompt and accurate relief distribution. Unfortunately, in fact bottlenecks in the last-mile distribution and requests from affected areas led to poor performa...

This paper examines how social interaction affects the choice to evacuate during a network formation process. The primary objective is to evaluate in detail the influence of other individuals by considering how influencers and entire network structures affect one-to-one interactions. This study proposes an analytical framework for the simultaneous...

This paper explores the variation properties of trip generation, trip attraction, intrazonal trips, and travel time under transport network disruption in Tenno district in July 2018 due to landslides. The empirical results obtained by using multiple passive transport data show that (1) traffic volume per hour on the National Route 31 went down to a...

The humanitarian logistics (HL) is important for minimizing the human suffering in the aftermath of a catastrophe. After the 2011 Great Japan East Earthquake and Tsunami, the poor HL practices, which is orchestrated by the government for the first time, caused many problems. From this experience, the HL system in Japan significantly has changed bas...

Deep learning methods are being increasingly applied in transport studies, while the methods require modellers to go through a try-and-error model tuning process particularly on choosing neural network structure. Moreover, the accuracy level also depends on other factors such as the type of data, sample size, region of data collection, and time of...

The final version of the published manuscript had several instances of error in referencing, especially in references with authors of the same name and year.

Since the cost and time required to finetune parameters in traditional short-term traffic prediction models such as traffic simulators are very high, the prediction models have been developed mainly for managing recurrent congestion, rather than non-recurrent congestion caused, for example, by disaster. Machine learning models are promising candida...

Post-disaster humanitarian logistics (PD-HL) is a vital science for minimizing human suffering in the aftermath of a disaster. A major obstacle to suitable PD-HL operations is that the PD-HL system is poorly understood. This paper proposes several directions to improve PD-HL operations based on theoretical and empirical analyses. Two catastrophic e...

Humanitarian logistics is important for minimizing the damage after a disaster. In Japan, based on past disasters, three empirical control strategies related to humanitarian logistics have been proposed: two relief transportation strategies, and an information strategy without ICT. This paper reveals the mathematical properties of these empirical s...

This paper explores variation properties of trip generation, trip attraction, intra-zonal trips, and travel time under transport network disruption in Tenno district happened in July 2018 due to landslides. The empirical results obtained by using multiple passive transport data show that (1) traffic volume per hour on the National Route 31 went dow...

This paper focuses on the effect of natural disasters on the population density transition. Emergency management needs demand forecasting by understanding the major demands during a disaster event. Mobile phone traffic is useful for understanding the demands because the behavioral dataset from typical surveys for ordinary demand pattern is impracti...

This paper focuses on the effect of natural disasters on the population density transition. Emergency management needs demand forecasting by understanding the major demands during a disaster event. Mobile phone traffic is useful for understanding the demands because the behavioral dataset from typical surveys for ordinary demand pattern is impracti...

In this paper, we improve the preprocessing phase of the ALT algorithm through parallelization. ALT is a preprocessing-based, goal-directed speed-up technique that uses A* (A star), Landmarks and Triangle inequality which allows fast computations of shortest paths (SP) in large-scale networks. Although faster techniques such as arc-flags, SHARC, Co...

The ability to find near-optimal traffic assignments for a very large network within a few days time will substantially contribute to reduce economic losses following major earthquake disasters. However, lack of efficient numerical tools and methodologies to solve this NP-hard problem within a reasonably short time is a major challenge. This paper...

Evacuation planning and management involves estimating the travel demand in the event that such action is required. This is usually done as a function of people's decision to evacuate, which we show is strongly linked to their risk awareness. We use an empirical data set, which shows tsunami evacuation behavior, to demonstrate that risk recognition...

This study reports the results of the analysis of probe data, collected in the periods immediately before and after the foreshock in Kumamoto on April 14, 2016. Data were gathered under actual urban traffic conditions, and the traffic activity evaluated. The study also identifies any issues to be addressed in future, based on this analysis. The ana...

In a disaster situation, people are easy to do similar behaviors of others because they don't have enough disaster-experiences to decide by just themselves. Our local interaction based model evaluate influences of others' behaviors to understand evacuation timing. The proposed model introduces a preference of inequality aversion on spatial and soci...

Several solution methods have been proposed to calculate a user equilibrium solution in a dynamic traffic network. Finding a stationary distribution of a Markov chain that model drivers' day-to-day route choice behaviours can be an alternative to solving an equilibrium solution. In this paper, we adopted a physical-queue model because it can captur...

This paper focuses on a decision making of evacuation start timing. This primary objective is to account for a dynamics of heterogeneity in expected utility. Decision-makers don't have the correct expected utilities at the time of inexperienced disasters. We extend a dynamic discrete choice model for the dynamics of heterogeneity. Our parameter est...

The optimal control is needed to prevent a traffic congestion for evacuation in a tsunami inundated area. This paper proposes a dynamic inflow control model on intersections and aims to minimize the time required to conclude evacuations. This model treats the flow conservation, the FIFO and the physical queues in a many-to-one network. The Pontryag...

In this study, we formulated an evacuation timing model and a selection model of evacuation-chains with delay penalty. The sets of trips for up to the safety spaces under disasters are defined as evacuation-chains and these chains influence the start time of the first trip and the start time of evacuation. Road congestions are also caused by the tr...

By treating human relationships as networks, disaster response planners can capture the features of cooperation behaviors between residents, providing valuable insights for effective evacuation planning. In this paper, we outline residents’ evacuation behaviors during the 2011 Great East Japan earthquake and resulting nuclear disaster and tsunami....