Hirotaka Koike

Unevenness of Intersection Pavement and Bicycle Safety

Bicycles are environmentally friendly and easy to operate. However, the bicycling environment in Japan is inadequate compared with many developed countries. Bicycle accidents have been increasing in recent years, and safety measures are needed to improve the bicycling environment. Although road surface conditions have improved, as reflected in the recent barrier-free policy for elderly and disabled pedestrians, an uneven surface between the road and the crosswalk can help to reduce accidents by reducing running speed. Because the most frequent type of bicycle accident is a collision with a car at an intersection, the accident-prevention potential of an uneven surface at an intersection crosswalk was examined. Students were asked to run along specific routes, and speed and vibration changes when they passed through intersections were measured. On the basis of the results, an analysis was made of what road environments would benefit from an uneven crossing surface. An uneven surface was found to reduce speeds at intersections with limited sight distance. However, other appropriate safety measures must be applied to reduce bicycle speed when an uneven crossing surface cannot be used because of the barrier-free policy.

Modal Shift Mechanism in the Transition Period from Bicycle User to Automobile User

As motorization spreads worldwide, concern is growing about the adverse effect of automobiles on energy resources and global environmental problems. A way to alleviate excessive dependency on automobiles is to promote bicycle transportation. However, it is difficult to increase bicycle usage except in some European countries, such as the Netherlands. In Japan the bicycle is commonly used from childhood through high school, but a rapid shift to the automobile takes place at college age. College students were surveyed by questionnaire on their bicycle use patterns and automobile ownership, along with bicycle use in their hometowns. The statistical analysis shows various relationships among population size of hometowns, regional characteristics, individual favoritism toward bicycles, financial condition, and so on. A clear difference was found between two groups of hometown regions for present bicycle usage patterns: those from large metropolitan areas and those from smaller regions. The transportation systems in cities and different population sizes influence bicycle use and favoritism toward bicycles, which in turn affects the present bicycle use level. Finally, the study reveals four factors that affect the modal shift from bicycle user to automobile user during the college-age period: physical environment, financial aspects, past experience, and favoritism toward bicycle use. These factors should be incorporated in designing bicycle transportation policy in urban areas.

Transportation impact assessment on urban development using NETSIM

The equilibrium between land use and transportation system has been an important issue in the city planning. Transportation Impact Assessment is a measure to make the equilibrium by balancing the relationship between urban development and transport facilities. First, this paper discusses about the development patterns which do not cause the road congestion in a hypothetical city with grid type network structure. By using a traffic simulation model, NETSIM, maximum value of floor area ratio (FAR) to avoid congestion is calculated in various situations. The result shows allowable level of FAR is much underestimated than the current legal limitation level considering the existing road capacity. Next, the model was applied to the actual city area with the existing road network. After constructing network of wider city area in computer model, we simulate the traffic impact generated by new development in the CBD. It was found that road congestion due to the new development is observed not only on immediately surrounding road but also in much wider area in the city, because of the change of the shortest path demanded by other traffic flows.

Intention data analysis concerning influence that introduction of LRT exerts on traffic of senior citizen action

In this paper, we analyzed the result of survey carried out in Utsunomiya-city and examined the relationship between daily activity of senior citizen and behavior activation of them in the situation of LRT introduction. As a result. it was founded that senior citizen had intention to use LRT at the time of LRT introduction, and their going out activity remain latent. The result shows that, these activities are much more likely to be latent behavior especi ally in private purpose trip. This means the latent going out behavior of senior citizen are activated when LRT is introduced in Utsunomiya.

Development of Integrated Database System for Traffic Impact Assessment using Server Side Technology

This paper discusses the Integrated Database System for Traffic Impact Assessment. Traffic impact assessment requires various data for analysis. However, data are widely scattered and a large amount of time is needed to execute analysis. In order to solve these problems, we developed a system which consists of Web GIS Server and Web DB server. These servers use the Java Server Side Technology. As a result, information retrieval by accessing the system became possible, and the traffic impact assessment can be executed more efficiently. A case study to apply this system to large-scale suburban shopping malls proved the effectiveness of the system.

DEVELOPING A BARRIER-FREE MAP BY USING GLOBAL POSITIONING SYSTEM AND CELLULAR PHONES WITH DIGITAL CAMERAS

The recent enactment of the transportation barrier-free law in Japan emphasizes the importance of incorporating a barrier-free approach for any new road facility construction and for improvements to existing road facilities in urban areas. The purpose of this study is to develop barrierfree maps for people with various types of disabilities to help public agencies plan a barrier-free transportation system environment. Statistics show that technological progress and the explosive proliferation of cellular phone use in Japan has reached the level of two phones for every three people. In particular, new advanced cellular phones equipped with additional features such as a Global Positioning System (GPS) and digital cameras are gaining in popularity. The focus is on GPS cellular phones with digital cameras as a tool to collect barrier-free information on the streets. The digital photos and location information generated by the GPS are sent to a personal computer by e-mail. The gathered information is then stored in a geographic information system (GIS) database to display hazardous barrier locations with pictures and messages on a map. Actual field surveys were conducted in the central business district of Utsunomiya City using this method, and information was collected about various barriers for people with different types of disabilities. Barrier-free maps for different types of disabilities were then developed using the multilayer feature of GIS. By comparing hazardous locations for each group of disabilities, both common and differential characteristics were found and summarized in the form of a barrier-free map. Such barrier-free maps are expected to be useful to public agencies for providing a barrier-free transportation environment for people with all types of disabilities.

Research on the Fluctuation of Basic Unit of Daily Visitors to Large-Scale Retail Stores

The guideline stipulated in the Large-Scale Retail Stores Location Law enacted in 2000 is uniform across the nation and does not reflect the characteristics unique to local cities. Therefore, this paper examined the actual situations in Tochigi Prefecture, and proposed improvement of measures that conform well to local city environments. Basic unit of daily visitors was analyzed using the result of customer satisfaction level survey. The analysis revealed cause of fluctuation of basic unit of daily visitors that takes attribute and behavioral pattern of individual customer into consideration. In addition, a proposal was made with regard to the establishment of basic unit of visitors to other facilities such as furniture stores.

ASSESSMENT OF A GAP-ACTUATED PUSHBUTTON SIGNAL USING A TRAFFIC SIMULATION MODEL

A main concern with pedestrian crossings is the time that pedestrians are expected to wait before a traffic light changes. Pushbutton signal systems are mainly set to accommodate vehicular flow efficiency, and the interval for pedestrians to cross the street remains the same even if no vehicles are on the road or if there is a long gap between oncoming vehicles. Pedestrians often cross the road against the go-ahead pedestrian signal when they perceive an acceptable vehicular gap, sometimes even after pressing the pushbutton. Vehicles must stop even if no pedestrian is waiting to cross the street. This study examined a gap-actuated pushbutton signal via a traffic simulation model. The results show a substantial decrease in pedestrian waiting time with negligible effects on vehicular flow.