Yasuhiro Mimura

Effect Analysis of Intelligent Speed Adaptation (ISA) in Advisory Mode on Community Roads

Abstract ISA is considered as an effective measure to reduce traffic accidents. To make the possibility analysis, an experiment is conducted by using a driving simulator. The outputs from the simulator are analyzed combined with the ages and road conditions. The experiment shows that the ISA can improve recognition to speed limitation and drivers’ behavior. Furthermore, drivers react significantly to voice assisted ISA; audible advisories by the ISA such as reduction of speed are acknowledged by drivers concluding positive effects on traffic safety.

A Study to Develop an Information Providing System on Travel Time

This study aims to develop a travel time information providing system for the road users. By using the historical data collected from the probe-vehicles in Toyota City, we analyzed the effects of the factors such as what day of the week, what time period of the day, weather (fine or rainy) and characteristics of the region. Then we developed a travel time information providing system for a certain road section as a trial. To test the validity of this kind of system to make people to change their departing time periods, the travel times ahead of the designated time period and after are shown together with the fuel expenses and amounts of the CO2 discharge.

Long-term effect analysis of dynamic speed display sign in streets

In 2014, Dynamic Speed Display Sign (DSDS) was firstly introduced in the Japanese community streets. This paper is to make a discussion about its long-term effects since then. The traffic surveys and the questionnaire surveys have been conducted several times. The traffic flows, the vehicle speeds and the consciousness of the residents told us the effects contributing to the traffic safety have been continuous up to now.

Impacts of monetary incentive measures on the acceptability for intelligent speed adaptation (ISA)

In Japan, Mandatory Intelligent Speed Adaptation (ISA) or Voluntary ISA could be a new paradigm for urban driving speed management such as traffic calming in community streets, once it is widely disseminated. This study aims to analyze the impacts of various monetary incentive measures and individual attributes on the acceptability for several ISA installation. We conducted a stated preference (SP) surveys for the subjects who had attended in a 5-month Advisory ISA field experiment. Then we applied disaggregate model analyses to the response data. The main results were: that the acceptability for Advisory ISA is highest followed by Voluntary ISA and then Mandatory ISA; that the acceptability for ISA that operates only on community streets is high; that the acceptability becomes higher as the age of the subjects becomes higher; and that the acceptability becomes higher as the amount of the monetary incentive becomes greater, but the marginal effect becomes lower. In conclusions, the monetary incentive meas...

Effects of Intelligent Speed Adaptation on Elderly Drivers’ Driving Behaviors and Mental Workloads

This study investigates the potential impacts of implementing mandatory and advisory intelligent speed adaptation (ISA) for elderly drivers driving on neighborhood streets. Using a driving simulator, driving behaviors such as vehicle speed and position of the gas pedal were analyzed. In addition, the mental workloads that could be represented by pupil dilation were measured using an eye camera device. Because elderly drivers tended to drive below the speed limit, implementation of ISA had little effect on reducing the speed driven at on neighborhood streets by elderly drivers. However, the implementation of ISA did serve to significantly reduce the mental workload for elderly drivers.

An analysis on excursion characteristics of electric assist bicycles by travel behavioral comparison based on trajectory data

Electric assist bicycles which are becoming a part of modern life have the possibility to promote bicycles excursion and the potentiality for the new travel mode responsive to the hilly landform and the aged society, so that it is important to verify practical effectiveness of them. In this paper, an analysis of effects of electric assist facilities on the excursion of bicyclists is conducted by comparing the travel behavior of the electric assist bicycles with that of the normal bicycles, using the trajectory data of the users of rent-a-bicycle in the urban area. As a result, it is shown that the use of the electric assist bicycle increases the travel distance and the coefficient for the utilization of slopes and this tendency is particularly true respect with the elderly, and that the running speed is less influenced by the longitudinal gradient value of the slopes.