Volume 5, 2007

Vol. 5, No. 1, October 2007

Research papers

Number: 04-02
Type: Research Paper
Pages: 1-6
Title: Mapping Personal Trip OD from Probe Data
Author(s): Edward Chung (Institute of Industrial Science, the University of Tokyo)
Masao Kuwahara (Institute of Industrial Science, the University of Tokyo)

Received: 25/04/2006
Revised: 27/10/2006, 17/11/2006
Accepted: 27/12/2006

Abstract: The paper analyses the expected value of OD volumes from probe with fixed error, error that is proportional to zone size and inversely proportional to zone size. To add realism to the analysis, real trip ODs in the Tokyo Metropolitan Region are synthesised. The results show that for small zone coding with average radius of 1.1km, and fixed measurement error of 100m, an accuracy of 70% can be expected. The equivalent accuracy for medium zone coding with average radius of 5km would translate into a fixed error of approximately 300m. As expected small zone coding is more sensitive than medium zone coding as the chances of the probe error envelope falling into adjacent zones are higher. For the same error radii, error proportional to zone size would deliver higher level of accuracy. As over half (54.8%) of the trip ends start or end at zone with equivalent radius of ≤ 1.2 km and only 13% of trips ends occurred at zones with equivalent radius ≥2.5km, measurement error that is proportional to zone size such as mobile phone would deliver higher level of accuracy. The synthesis of real OD with different probe error characteristics have shown that expected value of >85% is difficult to achieve for small zone coding with average radius of 1.1km. For most transport applications, OD matrix at medium zone coding is sufficient for transport management. From this study it can be drawn that GPS with error range between 2 and 5m, and at medium zone coding (average radius of 5km) would provide OD estimates greater than 90% of the expected value. However, for a typical mobile phone operating error range at medium zone coding the expected value would be lower than 85%. This paper assumes transmission of one origin and one destination positions from the probe. However, if multiple positions within the origin and destination zones are transmitted, map matching to transport network could be performed and it would greatly improve the accuracy of the probe data.

Keywords: Probe, Mobile phone, GPS, Origin destination, Location based system


Number: 04-11
Type: Research Paper
Pages: 7-16
Title: ARCHISIM: a behavioral multi-actors traffic simulation model for the study of a traffic system including ITS aspects
Author(s): Espié Stéphane (INRETS-MSIS)
J. M. Auberlet (INRETS-MSIS)

Received: 09/06/2006
Revised: 01/12/2006
Accepted: 28/12/2006

Abstract: The simulation of the impact of a change in the traffic system is a key issue, both from the safety and the capacity standpoints. The behavior of drivers facing a new situation is extremely difficult to forecast, since human beings easily adapt their behavior in response to infrastructure and equipments. They will not always use them according to designers’ expectations. This often leads to incoherence between design and uses, which have a negative impact on safety as well as on capacity. The tegrated approach developed by INRETS-MSIS allows a systemic approach of changes in the traffic system, and it consists of a four stage iterative process which jointly uses a driving simulator and a behavioural microscopic traffic simulation model. To carry on studies according to this approach, MSIS team has designed a behavioural traffic simulation model and a driving simulator architecture, moth novel.

Keywords: Drivers behavior model, microscopic traffic model, multi-agent simulation, driving simulator, ITS evaluation


Number: 04-15
Type: Research Paper
Pages: 27-36
Title: Three Aspects of Merging Capacity: Their Stochastic Nature
Author(s): Mohamed Shawky (Nagoya University)
Hideki Nakamura (Nagoya University)

Received: 25/08/2006
Revised: 13/02/2007, 08/05/2007, 17/05/2007
Accepted: 23/05/2007

Abstract: The proper understanding of the fluctuation nature of merging capacity is essential for more effective management and control strategies of merging sections. This paper aims to analyze the stochastic nature of the merging capacity and breakdown phenomenon in Japan urban expressway on-ramp junctions as well as to investigate the impact of some factors on their distributions, such as geometric design and traffic flow characteristics. Cumulative distribution models of merging capacity are presented for three different traffic flow conditions: before breakdown, when breakdown occurs and after breakdown. In addition, two different breakdown probability models in terms of flow rate and occupancy measurements are provided. These distribution models are more realistic for ITS control applications of merging section than the single value concept of capacity that is currently used.

Keywords: Merging capacity, Breakdown phenomenon, Ramp metering systems, Expressway on-ramp junction


Number: 2007-02
Type: Research Paper
Pages: 37-45
Title: A Study on Visually Impaired Persons Support System utilizing Visible Light Communication Technology at Signalized Intersections
Author(s): Koji Suzuki (Nagoya Institute of Technology)
Motohiro Fujita (Nagoya Institute of Technology)
Yasuhiko Hayashi (Nagoya Institute of Technology)
Kazuyuki Fukuzono (SEIWA ELECTRIC MFG Co., LTD)

Received: 02/04/2007
Accepted: 05/07/2007

Abstract: In this paper, we analyzed the issues and needs that visually impaired persons feel on a daily basis at signalized intersections. And then we evaluated a visually impaired persons support system utilizing the visible light communication (VLC) technology that was developed in order to solve the problems by using the experiment and the questionnaire. As a result, it was shown that the guidance of VLC system enables them to cross safely and comfortably at signalized intersection. Therefore, it can be said that the potential of VLC system to support visually impaired persons crossing at signalized intersection is sufficiently high.

Keywords: Visible Light Communication technology, Visually impaired person, Signalized intersection


Number: 04-13
Type: Research Paper
Pages: 17-25
Title: Driver Behavior Model for ITS Evaluation System
Author(s): Makoto Kano (Center for Collaborative Research, University of Tokyo)
Tomoyoshi Shiraishi (Center for Collaborative Research, University of Tokyo)
Masao Kuwahara (Institute of Industrial Science, the University of Tokyo)

Received: 04/07/2006
Revised: 31/10/2006, 28/05/2007
Accepted: 28/05/2007

Abstract: In this paper, we introduce a driver behavior model that can show realistic behaviors of vehicle. We have developed the system which links macroscopic traffic simulator (TS) with driving simulator (DS). This system can evaluate various ITS services by observing and analyzing both the behavior of DS driver and the effect on the traffic situation. In this system, the behavior of vehicles controlled by this system is required to be similar to that of real vehicles. We construct the driver behavior model which contains sub-modules for perception of information about nearby vehicles, judgment and action selection, the modules are applied for various situations. Using this driver behavior model and a vehicle dynamics model, we can simulate realistic vehicle behavior decided by interactions with neighboring vehicles.

Keywords: ITS, simulator, driver behavior model


Number: 2007-07
Type: Research Paper
Pages: 47-54
Title: Evaluation of Stopping Behavior of Drivers in Dilemma Zone Using Driving Simulator
Author(s): Toshihiko Oda (Panasonic System Solutions Company, Matsushita Electric Industrial Co., Ltd.)
Yoshihiro Suda (Institute of Industrial Science, the University of Tokyo)
Shinji Tanaka (Institute of Industrial Science, the University of Tokyo)
Daisuke Yamaguchi (Institute of Industrial Science, the University of Tokyo)

Received: 10/04/2007
Revised: 03/08/2007, 10/08/2007

Abstract: A traffic signal control method called Dilemma-Free has been introduced for more than fifteen years. In this method, there is an important issue about driver/vehicle behaviors involving the reaction time of a driver for braking and the deceleration rate of a vehicle. This paper describes a study of the stopping behavior of drivers in the dilemma zone using a driving simulator, and a questionnaire survey to inquire test drivers about their decision whether to cross or stop at the intersections. Results of this study show that there is no clear difference in approach speeds between stopped and passing vehicles and the drivers decision in the dilemma zone is heavily influenced by the vehicle distance to the stop line. Additionally, questionnaire survey confirmed that the status of pedestrian signals is one of the primary factors influencing drivers decisions.

Keywords:dilemma zone, driving simulator, stopping behavior, dilemma-free signal control, amber signal


Number: 2007-01
Type: Research Paper
Pages: 55-62
Title: Development of a Safe Driving Promotion System by Displaying Driving Scores and Rankings
Author(s): Kazunori Shidoji (Faculty of Information Science and Electrical Engineering, Kyushu University)
Taro Kumagai (Graduate School of Information Science and Electrical Engineering, Kyushu University)
Satoshi Watanabe (ITS Eng. Dept. 3, DENSO Co. Ltd.)
Yuji Matsuki (Faculty of Information Science and Electrical Engineering, Kyushu University)
Takashi Nakamura (Graduate School of Information Science and Electrical Engineering, Kyushu University)

Received: 02/04/2007
Revised: 02/08/2007, 24/08/2007
Accepted: 27/08/2007

Abstract: A critical factor in preventing vehicle accidents is a sufficient following distance. However, most drivers follow the car ahead too closely. A questionnaire survey examined the reasons for close-following distance, which included preventing cars from cutting in, being in hurry, feeling safe with a short following distance, and unaware of what a safe following distance is. It indicated that close-following is due to hastiness and unawareness of driving behavior. Then the results were used to develop and test a new safe driving promotion system, which displays a driver driving score and his or her rank. Drivers should be encouraged by their driving scores and rankings which will directly rouse a competitive spirit and will induce self-consciousness. Furthermore, drivers behaviors were browsed on the Web. This system should help drivers realize a safe following distance.

Keywords: Reasons for close-following distance, Safe driving promotion system, Score and ranking display, Competitive spirit, Self-consciousness