-
Koichi SAKAI, Kentaro WADA, Shintaro ONO, Tsutomu KAIZUKA, Toshiyuki S ...
2018 Volume 70 Issue 2 Pages
57-62
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
It is necessary to conduct the traffic operation policy using intelligent transportation systems technologies, if road network will be used effectively under implementing the expressway’s network. On the other hand, it is necessary to evaluate the effective and safety of this policy in advance using virtual traffic experimental environment such as driving simulator in case of no precedent policy. In this study, traffic operation policy, items which should be evaluated, function and performance required of virtual traffic experimental environment, and elemental technologies and logical models were studied for prior evaluation of traffic operation policy of efficient utilization of expressway’s network.
View full abstract
-
Shintaro ONO, Toshiyuki SUGIMACHI, Tsutomu KAIZUKA, Koichi SAKAI, Kent ...
2018 Volume 70 Issue 2 Pages
63-68
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
A virtual environment for traffic experiments that reproduces various conditions on drivers, self/other vehicles, and infrastructures, is useful for evaluating technologies and measures. In this report, its techniques and quality of reproducing the real environment are summarized from diversified and systematic viewpoints, including vehicle dynamics, traffic engineering, and visual environment. Methods and technical issues in enhancing the reproducibility are also discussed, especially on visual environment under normal and abnormal conditions such as dark scene, bad weather, etc.
View full abstract
-
Koichi SAKAI, Takashi OGUCHI, Yoshihiro SUDA
2018 Volume 70 Issue 2 Pages
69-74
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
Recently, research and development activities of automated driving systems are strongly conducted domestically and abroad. In order to study social and industrial impact of automated driving systems and so on, authors established study team centering on university specialists and studied evolution of automated driving systems, social and industrial impacts, and consideration of advancement and deployment of automated driving systems such as technical issues, social acceptance, relationship to urban planning, business model, public character / taxes and fees, traffic management, ethical issues and legal issues from a civil law perspective.
View full abstract
-
Bo YANG, Takayuki ANDO, Wataru KUGIMIYA, Masaya SAKAMOTO, Keiji AOKI, ...
2018 Volume 70 Issue 2 Pages
75-78
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
There is a great expectation for automated driving technology to solve social problems including aging and labor shortage. In areas where aging is progressing, automated buses are expected to be an essential mean of transport for elderly people. To assist automated buses in passing through signalized intersections more smoothly, it is necessary to control the speed of the buses based on signal information. Signal cycles of ground traffic lights on the determined route are stored as information on the bus side. Therefore, the traffic light can be predicted in advance for the bus. When a red light is predicted to appear, the bus will decelerate in advance and perform speed control to avoid sudden braking. In this paper, a demonstration experiment of an automated bus performed at Ishigakijima this year would be reported.
View full abstract
-
Tsutomu KAIZUKA, Li HUANG, Manabu SHIMODAIRA, Katsutoshi INAGAKI, Kimi ...
2018 Volume 70 Issue 2 Pages
79-82
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
Blind spot monitors (BSMs), which inform a driver about the existence of the other vehicle at a blind spot, are installed on a driving simulator to evaluate their effectiveness during manually performing a lane change. The investigated BSMs are two: one is enable to tell the directional information, i.e., in which direction (left or right) the other vehicle exists; and the other is merely tells the existence of the other vehicle without conveying any directional information. The case after the transition from the automated driving to the manual driving is also investigated in this experiment.
View full abstract
-
Li HUANG, Tsutomu KAIZUKA, Masanori KOSUGI, Mitsuhiro KAWADA, Shinobu ...
2018 Volume 70 Issue 2 Pages
83-86
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
A driving simulator experiment was conducted to investigate the effectiveness of an alarm system that presents to the driver that another vehicle is present at the blind spot area when the driver freely changes the lane during manual operation. There are three types of alarming that use the indicator lighting or blinking on the door mirror in the direction in which another car at the blind is present, the vibration of the lever, both of the indicator and the vibration of the lever. We also examined the effectiveness of lane change during manual operation after switching from automatic operation to manual operation.
View full abstract
-
Takayuki HIRASAWA, Kenji KOUNO, Daiki TAMURA, Yoshihiro SUDA, Koichi S ...
2018 Volume 70 Issue 2 Pages
87-93
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
To answer increasing needs for personal transport transfer navigation to diverse local mobility at railway station even to cope with inbound tourism in accordance with development of transportation network and diffusion of mobile devices, a prototype smartphone application using digital watermark that links with information sign or digital signage has been evaluated with 10 subjects at mockup station. Experimental data illustrated merits of proposed method by both improving subjective understandability and shortening information search time.
View full abstract
-
Teruhisa TAKANO, Shintaro ONO, Hiroshi KAWASAKI, Katsushi IKEUCHI
2018 Volume 70 Issue 2 Pages
95-100
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
Fisheye cameras or wide-angle cameras used on cars will have various applications as kind of distributed sensors, and the image resolution can be enhanced by super resolution (SR) technique. However, when an object is observed while the car proceeds or by multiple cars, the object regions are often captured in quite low quality (low resolution, large blur), because of the lens character. Here, when applying SR, which images to use for inputs is a problem – more images including lower quality, or fewer with higher quality. We evaluate and discuss the quality (blur size) allowable to get good SR result, and consider to make it use for a requisite in observing road environment.
View full abstract
-
Koichi SAKAI, Takeshi OISHI, Shintaro ONO, Yasuhide OKAMOTO, Takayuki ...
2018 Volume 70 Issue 2 Pages
101-106
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
Visual information is a significant role in the road maintenance works because fundamentals of a lot of road maintenance works are visual confirmation of field status. There are a lot of information related to road maintenance works, but it is not easy to connect with this information and field status. In this study, the system connecting with the omnidirectional video shot on actual national highway and road maintenance information was created and the possibility of utilization of this system was studied through asking National Highway Office’s staffs for their opinion of this system.
View full abstract
-
Muhammad ABDULLAH, Takashi OGUCHI
2018 Volume 70 Issue 2 Pages
107-111
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
Pedestrian and vehicle conflicts at signalized intersections may result into serious injuries or even deaths. Many pedestrian signal phasing schemes exists in order to improve pedestrian safety. Leading pedestrian interval is such a phasing scheme to give pedestrians a head start to establish their presence at the crosswalk before conflicting movements are released. This paper evaluates the relative applicability of leading pedestrian interval (LPI),with respect to a commonly used phasing scheme i.e. concurrent pedestrian phase (CPP), by solving an optimization problem considering both efficiency and safety. Efficiency and safety indices are converted into monetary values to choose the more suitable pedestrian phase pattern simultaneously with optimal signal parameters under given input. The optimization problem consists of nonlinear objective function as well as nonlinear constraints. Therefore, it is difficult to obtain optimal solution using traditional nonlinear programming techniques. Hence, population-based heuristic optimization algorithms can be used to solve the problem in reasonable time.
View full abstract
-
Charitha DIAS, Takashi OGUCHI, Kasun WIMALASENA
2018 Volume 70 Issue 2 Pages
113-118
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
The knowledge on free-flow speed is important to evaluate the safety and efficiency of highway and expressway systems. Previous studies have either assumed a constant speed throughout the horizontal curve or modeled the speed as a piece-wise linear profile. In this study a novel approach, which is based on minimumjerk principle, is proposed to model continuous speed profiles on expressway curve sections. Other than evaluating geometric design consistency, output of this study may be useful in advanced applications, such as 3-D visualization of realistic vehicle movements in driving simulator and virtual reality applications, and trajectory planning of autonomous vehicles.
View full abstract
-
Yudai NAKATA, Kentaro WADA, Takashi OGUCHI
2018 Volume 70 Issue 2 Pages
119-123
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
In this paper, we present a novel dynamic system optimal (DSO) problem in which total travel time over a road network and road deterioration caused by vehicles’ live load are both accounted for. We first formulate a model that optimizes the aforementioned two objectives by (1) evaluating the degree of deterioration by means of marginal maintenance cost of each link and (2) only using the traffic volume of large vehicles, which have dominant effect on road deterioration, to estimate the increase of the maintenance cost. Then, we compare our proposed problem with the conventional DSO problem to analyze how the consideration of road deterioration can affect the optimal traffic flow.
View full abstract
-
Jiahua ZHANG, Miho IRYO-ASANO, Charitha DIAS
2018 Volume 70 Issue 2 Pages
125-129
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
Pedestrian fundamental diagram (PFD) is a basic tool to evaluate pedestrian flow. However, the characteristics of PFD at different bottleneck types have not been well understood so far. Through a laboratory experiment, this study derived high resolution PFDs in the upstream of bottlenecks with different properties (i.e., width and service rate) by using a simplified voronoi diagram method. It was found that velocity distributions with the same bottleneck width but with various service rate varied significantly while the density distribution did not. In addition, PFDs with higher velocity and maximum flow were generated after repetition of the experiments.
View full abstract
-
Yu HASEGAWA, Miho IRYO-ASANO
2018 Volume 70 Issue 2 Pages
131-135
Published: March 01, 2018
Released on J-STAGE: March 30, 2018
JOURNAL
FREE ACCESS
The effectiveness of experiments by simulative approaches using virtual reality( VR) tools has been improved recently. This situation leads to increasing the reliability of pedestrian experiments in VR system. However, conventional pedestrian behavior models, which have not been developed for VR, could cause unnatural behavior if the models are simply applied to VR. Therefore, this study proposed a Social Force Model-based improved pedestrian behavior model for VR simulation, in which pedestrian characters walk in the more natural way. The result of this study also provide the new method for evaluation of pedestrian models, that helps deeper understanding of pedestrian behavior.
View full abstract