Traffic state estimation (TSE) is essential for road traffic management. However, TSE covering wide spatial domain is practically difficult due to the technical limitations regarding data collection. To ll this gap, this study proposes a TSE method for wide spatial domain using remote sensing by small satellites and mobile sensing by probe vehicles. Specically, the remote sensing is supposed to measure traffic density in the entire road network with few hours interval, whereas the mobile sensing is supposed to measure traffic speed continuously. The proposed method estimates the traffic state by combining these measurements by using data assimilation based on traffic Žow theory. The notable feature of the method is that it endogenously estimates fundamental diagram parameters and penetration rate of probe vehicles, meaning that the method is completely free from detectors. The performance of the proposed method was evaluated by numerical simulation. It was found that few hours time interval of remote sensing and 10% or more penetration rate of probe vehicles were required for accurate estimation.

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The Nankai trough Earthquake, which might occur in the near future, may cause long-term flood in the central part of Kochi city. It is anticipated that a lot of vulnerable patients will be left in the flooded area after the disaster. To mitigate the effect, related local institutions have examined a disaster recovery plan; however, there is only the examination of the number of required rescue boats. This study proposes a model that transports a patient by boats. The model can show boat allocation which has maximum accessibility index under the constraint of the number of patients and the distance from rescue base to devastated area. As a result of applying the proposed model to Kochi city, it clarified that the number of bases that boats are allocated are likely to increase in the case that constrains are weak. In addition, rescue simulation which was developed in this study calculated travel time for transporting and detected the location where is necessity to be supported by other institution.

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In this study, both the differences of movements between autonomous vehicle and general vehicles and the impacts of autonomous vehicle on traffic flow were analyzed by the observation data of demonstration experiments in Aichi prefecture. As the results of analyses, it was found that autonomous vehicle can hold the speed at a constant level on basic section compared to general vehicles. In addition, it was revealed that the characteristics of following behaviors of autonomous vehicle varied with the type of leading vehicle. At signalized intersection, it was confirmed that the start-up response time of autonomous vehicle was longer than that of general vehicles. Furthermore, it was found that the speed differences at the exit of intersection between autonomous vehicle and general vehicles were little for through traffic, but the differences for right-turn and left-turn traffic became large. For the saturation flowrate, the values became lower by the commingling of autonomous vehicle with traffic flow.

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In this study, we investigated whether community buses with fewer users would be replaced with the taxi (not shared taxi) in the view point of local transportation policy. Firstly, the meanings of public transportation provided by taxis is discussed from each side of municipalities, taxi operators, taxi drivers. Secondly, as a case study, we estimated the cost saving effect of local public transportation in Toyota city, Aichi prefecture, Japan. As a result, it is indicated that 1) it can be expected that taxi can be used as a local public transportation in a situation where the density of transportation demand is low, 2) it is suggested that operating expenses of a local public transportation can be reduced by 20 - 70%, 3) As a regional characteristics, the areas which have an inefficient bus route with a large detour ratio are suitable for replacement community buses with taxi with mileage system fare.

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This study paid attention on the fact that many drivers who go to a wrong direction when driving on a expressway tend to make an illegal reverse running before an IC tollgate to which the drivers get off the expressway. To grasp the reasons for this behavior, this study aims at classifying the behavior patterns of the drivers who went to a wrong destination. Firstly, cluster analysis whose variables were the evaluation values on loss consciousness on fee and time due to taking the wrong directions, and the evaluation values of driving behaviors estimated from the answers on safe driving self-diagnosis at driver license renewal was conducted so as to classify the answerers into four groups. Then, the risks perceived by the drivers of each group before the tollgate were considered. As a result, it was found that drivers with different driving behavior perceived different kinds of risks before the tolls.

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In proportion to the increase of elderly drivers' driving on expressways, the number of wrong way driving and accidents caused by elderly drivers, increase in recent years. In this situation, many scientists research the traffic safety targeted at elderly drivers on expressway, such as Tada et al. extracted the characteristic patterns of elderly drivers' accidents on expressway, and Sakamoto et al. analyzed the driving behavior of elderly drivers at a toll barrier of expressway main line. NEXCO Central is considering the supporting contents for elderly drivers by expressway managements and devices in cooperation with academics. And in order to extract the differences between elderly and non-elderly drivers in driving characteristics and issues, we surveyed the examinee's driving behavior at a tunnel, a toll barrier, and a merging traffic flow at interchange on actual road, referring to previous studies. As a result, we revealed that some elderly drivers could not smoothly flow in from an accelerating lane at interchange, and that the elderly drivers' visual perception to information signs was insufficient compared with non-elderly drivers.

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The necessity of reconsidering the passenger car equivalent (PCE) of heavy vehicles have been pointed out because of the improvement of heavy vehicle performance. Besides, the road network in Japan is almost completed and it is expected that the road functions will be differentiated and the traffic characteristics of heavy vehicles will also change. Therefore, in this study, the relationship between the effect of heavy vehicles on capacity and the road hierarchy and traffic characteristics was clarified by field observation data and the characteristics of PCE were analyzed. As a result, the PCE has different values depending on the road hierarchy, and it became clear that these differences are largely influenced by the proportion of semi-trailer. In addition, it is clarified that the PCE is smaller than the specified value, which suggests that not only the improvement of the heavy vehicle performance but also the increase of headway of the passenger cars may be influenced. Furthermore, methods for determining the PCE based on the road hierarchy and traffic characteristics were discussed.

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Similar with the vehicle evacuation form Hurricane disaster, people strongly expect that “contraflow” policy which permit one-way traffic in two-directional road sections may enhance the effectiveness and safety of tsunami evacuation. However, coast-heading traffic have been observed during actual tsunami disasters, we cannot simply inhibit those coast-heading traffic. Contraflow sections should be designated to minimal sections where the effect is surely expected. In a previous study, we constructed a tsunami evacuation model allowing coast-heading traffic for further on-route vehicle riding of people who cannot drive themselves. In this study, we incorporate optimization of contraflow section into the model, and apply to a municipal scale virtual network. As a result, fewer contraflow sections are designated, when the percentage of drivable evacuee is small and coast-heading traffic are more important for on-route vehicle riding. We also investigate the characteristics of the road sections which are always selected as contraflow section regardless of the parameter variations.

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“Guideline for creation of safety and comfort bicycle environment” was enacted in 2012. The bicycle environment has been improved, and bicycle lanes has been implemented in Japan. However, on the bicycle lanes, there is no physical objects such as curbs separating between the bicycle space and the car space, thus both traffic users have no choice but to drive while affecting each other more than ever. Therefore, in this research, in order to clarify the influence of the bicycle cycling on the same space as car on the car traffic, we conducted experiments in the real road space and the virtual road space. A bicycle for measuring the running behavior of the car was developed and a driving environment was created on computer graphics, and the influence on the car speed and the separation distance when the car driver passed the bicycle were examined. Furthermore, the characteristics of behavior related to overtaking the bicycle and the factors that influences on overtaking behavior were clarified.

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Since Japan is a super aging society, maintaining safe public transportation service is an important issue. Nevertheless, the number of elderly bus drivers is increasing as rapid aging of the population continues. Our previous study showed that elderly drivers tended to perform less scanning behavior than non-elderlies where driver should simultaneously pay attention to multiple hazards around the vehicle. However, few studies have investigated to understand characteristics of elderly bus drivers’ behavior. In this study, we measured elderly bus drivers gaze behavior while driving in real traffic conditions, and compared the measured data to those of non-elderly bus drivers (drivers in training and bus instructors). As a result of our analysis, we found out that elderly bus drivers performed significantly less checking behavior than even drivers in training in traffic scenes frequently occurred in a daily service, especially traffic scenes where driver should simultaneously pay attention to multiple mirrors and traffics around to prevent accidents.

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The development of autonomous driving technology is pushed forward rapidly to improve the safety and smoothness of road traffic. However, few studies have investigated for evaluating how autonomous vehicles affect surrounding vehicles movements and drivers’ behaviors in mixed-traffic flow consisting of autonomous vehicles and manually driven vehicles. In previous studies, focusing on adaptive cruise control (ACC) system, we simulated mixedtraffic flow consisting of ACC vehicles and non-ACC vehicles at nearly critical density on driving simulator, and investigated characteristics of the traffic flow. In this study, we focused on higher density traffic flow than previous study and evaluated the safety and smoothness of the traffic flow and drivers’ behaviors. Even though the smoothness was improved with the increase of the mixture ratio of ACC vehicles in the results of this study, a case where a potential accident risk increased was observed with reference to the safety. In addition, it was revealed that drivers could afford to pay attention to their own driving and surroundings by the ACC vehicles being mixed.

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It is known that the traffic performance of expressways changes depending on road conditions, driving environment conditions (weather conditions), and traffic conditions. Among them, the traffic conditions depend on the attributes of the driver and the performance of the car, and since there was a possibility that it changed over the years, the study analyzed the time series change of QV. As a result of comparing the QV figures of 39 points from 2003 to 2016, it was confirmed that the free flow velocity, the maximum traffic volume, and the queue discharge flow have declined over time at almost all points. Moreover, it realized that the maximum traffic volume decreased by about 7% on average and the average velocity decreased by 7 to 9%. From these results, we assumed the reason why the traffic performance declined over time is not the characteristic of the spot, but the change of the situation of the whole society, and we considered the factors.

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In Japan, according to the statistics of the number of deaths by road type, the rate of decrease in the number of deaths and injuries of roads (residential street) with a roadway width of less than 5.5 m is smaller than that of arterial roads. Also, since there are many casualties and injuries in young children 's walking accidents, it is important to ensure the traffic safety of children’s pedestrians on residential streets. However, there are not many things studying children's pedestrian traffic safety, focused on the awareness of drivers who are at risk of hurting children's pedestrians. In this research, we focused on the consciousness of the driver and clarified the stress consciousness of children’s pedestrian on residential streets. As a result, it became clear that the walking position of a child affected stress consciousness. In addition, classification into high and low consciousness levels and factor analysis using binomial logistic regression analysis revealed that family composition, awareness of residential streets, driving consciousness influenced driver’s stress consciousness.

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In recent years sharing economy, a system in which participants interact in a direct and cooperative manner to consume goods and services has spread widely. In the transportation field ridesharing in which more than one person share a vehicle to make a trip is also spreading in various forms. Ridesharing is an effective use of resources, and it can be expected not only to reduce personal travelling expenses, but also to create great value for society, such as reduction in traffic volume, alleviation of air pollution and provision for a mode of transportation. In this research, the matchability and effectiveness of ridesharing in local cities were analyzed by applying a stable matching method. Results suggest that an increase participation rate of ridesharing and appropriate adjustment of ratio between drivers and passengers might lead to a reduction of traveling expenses and total mileage while minimizing the negative utility generated in ridesharing.

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Although the crackdown was strengthened by the revision of the Road Traffic Law in 2006, still many illegal street parking has occurred. This is caused by not thoroughly enforcing illegal parking control. In central business district, demand for short-time parking such as cargo handling is increasing, and it is considered that on-street parking allowable space dealing with this demand is necessary. In this research, we proposed on-street parking allowance space on the main arterial road in consideration of the traffic flow and on a narrow street in consideration of the influence on pedestrian from the field survey results. By suggesting newly important crackdown space from this research, we clarified that the total crackdown distance is about half compared with the current situation. According to the concept of parking cost, it was revealed that illegal parking costs will be higher than legitimate on-street parking by doing a patrol once an hour. It also showed that it is effective for suppressing illegal parking by the proposed crackdown frequency.

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Safe and smooth road traffic becomes difficult more often, because of a shortage of parking facilities for sightseeing buses in big cities. While the number of foreigners visiting Japan has increased, and the demand for sightseeing buses is rapidly increasing, Foreign Independent Tour (FIT) may increase in the future. Therefore, in big cities, parking measures for sightseeing buses by the operational improvement approach will be effective. This study clarified the effects and problems of operational parking measures for sightseeing buses in big cities from the results of a license plate survey, traffic volume survey, stakeholder interviews and others, by the case study in Asakusa District in Taito City, Tokyo Metropolitan. Additionally, we described the actual situation of uncertainty that hinders efficient operation of parking facilities. Finally, we considered the requirements that parking measures for sightseeing buses approached from the operational improvement would be effective in tour sites of big cities.

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The present study proposes a road lighting system that uses pro-beam light distribution. The visibility of a pedestrian who is crossing the road and is illuminated by a conventional road light is known to depend on the relationship between the driver’s position and the pedestrian’s position. Pro-beam road lights are a fundamental solution to the problem of enhancing the visibility of pedestrians crossing the road. Based on the author’s previous studies, the present study presents two novel types of pro-beam luminaires that incorporate LED lamps to show a slightly different light distribution and reveals the effects of these pro-beam road lights on the visibility of pedestrians crossing the road at night. The study includes two experiments. One is a field experiment to evaluate the visibility performance of these pro-beam road lights at a test track. The other is a laboratory experiment that uses images to determine when pedestrians crossing the road are detected. The two types of pro-beam road lights were found to afford considerably greater visibility performance in the driving lane than conventional road lights provide.

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This study analyzes the influence of autonomous vehicle (AV) on urban transportation using agent-based simulation. Assuming an AV share of 100%, the modes considered are private AV, car share AV and ride share AV. 10 AV spreading scenarios are defined based on AV use patterns and the dispatch algorithm in the case of sharing AV scenarios. MATSim which features co-evolutionary algorithms is used for the simulations. The target area is Numata City and Tone County in the northern part of Gunma Prefecture. The Gunma Prefecture 2015-2016 person-trip survey is used for calibrating the simulations. Findings suggest that even in rural cities highly dependent on cars, AV sharing can result in an increase in total travel distance, a reduction in the number of required vehicles, and relaxation of road congestion. Furthermore, while ride sharing might contribute to the reduction of environmental burden, excessive ride sharing might reduce the users’convenience considerably.

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The present study was undertaken in order to get knowledge about the influence that travel behavior and transportenvironment on health. We analyzed a positive analysis looking at the relationship between travel behavior, transportenvironment such as the accessibility to public transport and health through statistical data and survey data. It has followed that the result improved probability of past research and indicate the relationship between travel behavior, transport-environment and “a risk of decease” such as cardiac insufficiency. Moreover it was suggested that transportenvironment divided by the unit that was more detailed than past study have relevance to the rate of various diseases treatment accepter. In line with this, the transport infrastructure in a more detailed area in the city could have an influence on the health. This study makes a contribution to developing and expanding mobility management measures can effectively change travel behavior and encourage a mode shift from private cars to public transit.

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In Japan, there is little discussion about traffic signal control for bicycle traffic. Bicycle traffic running through roadway obeys traffic signal for automobiles. However, since clearance interval of traffic signal for automobiles is decided based on automobile’s speed, it is inadequate for bicycle traffic and then there is some possibility of leaving bicycle traffic at signalized intersections when traffic lights change. In this study, observation survey was conducted at some signalized intersections and the collected data were used to analyze problems of bicycle’s clearance. As a result, there were some factors, for example, traffic signal control and geometric structure of signalized intersection, of leaving bicycle traffic in signalized intersections. Analysis also found that clearance interval for bicycle traffic that is calculated by using the speed of bicycles was larger than that of traffic signal for automobiles. From the results of observation survey, this paper mentioned knowledge for making a guideline of traffic signal control considering bicycles.

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In recent years, driving support systems have begun to be installed in the real field, and expectations for improvement in safety and efficiency by autonomous vehicles are increasing. However, these expectations are not necessarily realized at the stage of popularization of autonomous vehicles. Particularly, at signalized intersections, because vehicles interact with each other in a complicated manner, efficiency may be affected depending on the setting of the behavior parameters of autonomous vehicles. Thus, this paper analyzes the influence of setting of parameters of autonomous vehicles on capacity of through lanes at signalized intersections by using simulation and model equation, and the capacity is calculated by using simulation result considering parameter settings and mixture ratio. As a result, while it became clear that the cycle length can be shortened by spreading of autonomous vehicles, it is suggested that by inputting discreet setting of the parameters of autonomous vehicles, the efficiency may decrease.

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Though business truck operators finally make decisions on route choice between expressways and ordinary roads, contracts with their consigners must affect their decisions. In this research, we first conducted hearing survey on operators and confirmed that contracts influenced the route choice behaviors. In addition, there are some operators which don't obtain enough profit and cannot use expressways without considering expressway tool or travel time. Based on the results of the interview survey, we conducted SP survey on route choice for all companies except Sado area and coffin carriers which join the Niigata Prefecture Truck Association, Finally, we propose two models: one is a binary logit model and another is a captive-conscious route choice model considering the relationship between operators and consigners, and confirm that the later model is better in terms of the likelihood ratio, and attributes of operators can distinguish captive group and selective one.

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The public transit navigator system is a system that uses a combination of public transport schedule information that changes minute-by-minute in real time, and of time tables and other fixed information, to support users’ optimum route selection of public transport systems through mobile phones or PCs. Bus-Net, a public transit navigator system, was introduced to Tottori prefecture in Japan. In the transit navigator system, the user’s search information, such as the departure place and destination, the time such information was specified and search request time, is recorded as log data. This study defines prior search time as the time difference between the search request time and the specific departure or the arrival times. And then, this study verifies factors that influence the prior search time using survival analysis. The estimation results show that prior search time is influenced by the departure place and destination, the devices utilized, the weather on the day that the searches were requested, and so on. In addition, this study shows that the estimated results enabled for the prediction of prior search time corresponding to the search situation.

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In our country, there are parking meter section as interim using of road space in a case of capacity of off-street parking facilities is insufficient. In parking meter section, legitimate on-street parking is admitted by parking in a frame, paying parking fee using parking meter or parking ticket, and finish parking within the set parking time limit. Until now, operation of parking meter has been mainstream that parking fee is 300 yen and parking limit time is 60 minutes. However, new operation that parking fee is 100 yen and parking limit time is 20 minutes started some areas centering on Tokyo fitting recent short time on-street parking demand.
This study, I analyzed the actual situation of on-street parking in parking meter section in which operation parking meter with different parking limit time and parking fees are mixed. And I revealed influence of difference in operation method on street parking behavior.

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This research aims to investigate the relationships between the accident risk and various factors such as traffic states, road geometries and weather conditions. Abundant study has been conducted to identify the accident risk factors for inner city highways. However, few has been reported for intercity expressways. This research first defines the traffic environment categories. The category considers traffic states, horizontal and vertical alignment, tunnel and precipitation. In defining the traffic states, this research proposes the method to identify the four states: free flow, capacity flow, congestion and mixed-state flow. Then, the accident risk is calculated for each traffic environment category to reveal the effect of the factors on accident risk. The results identified that the risk of sideswipe accident in mixed traffic state is higher in multiple lane sections. The study also revealed that the risk of crash accident is higher in the entrance of tunnels. Future research needs include the development of accident risk estimation model based on the findings from this study.

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The proportion of elderly drivers’ accidents to total in Japan has been increasing steadily over time, therefore it is urgent to strengthen effective safety measures. Because there is a wide range of variations in influences with advancing age acting on physical, cognitive and psychological abilities, driving properties of elderly drivers vary a great deal. To gain a new insight from breaking the driving behaviors down into patterns, as well as to view the problems of elderly drivers in broad perspective such as a statistical accident analysis is important.
The authors acquired driving behavior data in everyday life of elderly drivers using the driving recorders, and examined the diverseness of abrupt deceleration patterns and the relationship between safety confirmation behaviors and individual properties. Consequently we found that road or traffic circumstances in case of an abrupt deceleration differ according to individuals and the relationship to safety confirmation varies by individual property index.

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Approximately 200 instances of Wrong-way driving occur in Japan every year. Countermeasures against Wrong-way driving such as arrow pavements are being implemented to prevent these. However, even after introduction of countermeasures, wrong-way driving still occur, and it is necessary to verify the effect of the countermeasures. More than 70% of wrong-way drivers are elderly individuals, including those who are suspected of declining cognitive function.
 In this paper, we examined the effect of visual countermeasures on patients with MCI by using a computer graphics movie and measuring the reaction time which is the time to identify wrong-way driving. As a result, in PA entry section, the arrow pavement had the same effect on patients with MCI compared with healthy elderly individuals. In IC exit section, the “stop” sign and the arrow pavement had small effect, and “stop” signboard increased the effect. However, in all cases, it was found that the problem remains in the easiness of judging Wrong-way driving.

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The purpose of this paper is to develop a spatial computable general equilibrium (SCGE) model that is capable of analyzing the effect of the timing of road development on the population distribution. To this end, we extended the SCGE model developed by Takayama et al.¹⁾ ("Development of a spatial computable general equilibrium model with factor mobility and agglomeration economies," Journal of Japan Society of Civil Engineers, Ser. D3, Vol. 72, No. 2, pp. 211-230, 2016) to represent the transportation network in Japan. We then conducted the following two types of counterfactural analyses that replicate the road development from 1986 to 2005: 1) a case where the interregional distance is gradually changed at 5-year intervals, 2) a case where the interregional distance is changed at once. Finally, we showed that the results of these analyses are signi?cantly different, which implies that our framework is capable of representing the effect of the timing of road development on the population distribution.

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This paper analyzed the relationships between street environments and children’s gait characteristics. This study uses plotting the point where the children passed the section of 20 meters in the school road. Through the data, we examined how the children’s gait and behaviors are changing and the points assign to mesh. The data were classified into 3 groups according to road width, and analyzed. The 3 main conclusions of this study are as follows: 1) In the third group a large width, the passage positions of children are concentrated and in the first group a small width, they are dispersed. 2) In the second group, the passage positions of children concentrate with increasing traffic volume. 3)Amount of movement of children on school road is large as compared to estimated shortest distance. And the amount of movement to the side where the boundary condition is released is large.

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In this study, we compared Sapporo with Tokyo about how to use parking meter. As a result, having use or not of the payment and indication line of the fee (frame) could know the difference of some parking actions and was able to show some problems about the use of the system that considered the difference of the city. The setting of the limit parking bay is shown as a measure corresponding to the short parking demand on the road in Road Traffic Act Article 49 at time. We usually install a parking meter or parking tickets in the section concerned and manage it to carry out this regulation effectively. It is approximately 30,000, and the number of these setting in our country (2012) is a value smaller than 2,200,000 of the parking lot, but is important as a measure to realize the access function of the street effectively.

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For securing the safety of pedestrians, it is necessary to create an environment where pedestrians and vehicles coexist safely in the same space. In this research, in order to clarify the road patterns where pedestrians and automobiles can coexist safety, the differences in traffic conditions on residential roads with different road surface patterns for roads without sidewalks are grasped. In the research, by video survey and ETC 2.0 probe data survey, the traffic conditions such as vehicle speeds, passing positions of users, and other behaviors were analyzed, on the selected road sections where the widths were roughly equal and the surface patterns were different. As a result, it seems possible that the vehicle speed can be reduced to 40 km/h and the average speed can be reduced to 30 km/h by improving the road surface patterns, and it is thought that improving road surface patterns is useful for constructing a safe residential road space.

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In the large metropolitan areas, usage of grounds and shallow undergrounds are becoming more sophisticated and complicated. Therefore, the construction of the expressway using the deep underground is progressing to improve the transportation network. At the junctions of deep underground expressways, from the aforementioned reasons, there are cases where sudden changes in the road shape are concentrated in relatively short sections such as steep slopes from above grounds to under grounds, split or merge points of the rump tunnels, and sharp curves of the ramps. However, the impact of changes in road structures, usage of deep underground, on vehicles and drivers is not understood properly. In this study, by an indoor driving experiment using the driving simulator, we investigated the behavior of vehicles and drivers at junctions of deep underground expressways. As a result, we confirmed the necessity of attracting attention, which is a standard safety measure. Additionally, we clarified where the risk of rear-end accident is high and tried to grasp the factor.

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Pavement markings provide drivers with important information about their position within their own lane. The development of a pavement deterioration estimating model has been needed for road administrator to appropriately achieve asset management, so that the life cycle cost of pavements can be minimized in long term. This study purpose was to develop pavement deterioration rate curves for road edge line markings. To accomplish these purpose, this study investigated the photo to take measurements on 200 samples based on road surface data collected from selected sections under arterial road in Chiba prefecture. In this study, the pavement performances of road edge line are described by the paint stripping ratios are modeled by segmented regression model. Then, in order to estimate paint stripping ratio, models were developed as a function of key performance variable which is the pavement over time. As the results, road edge line pavement markings should be painted at least once seven years.

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In this study, we estimated the effect of constructing new expressway on macroeconomy and tinter-regional distribution of population and production in Japan by using an existing simulation model with some improvements. The result showed that constructing new expressways contributes to the Real GDP growth. On the other hand, in the scenarios of “nation-wide construction” and “Kanto-area construction”, the population and production were concentrated more in Kanto Area and local areas declined. But in the scenario of “other-than-Kanto-area constrution”, the population and production were dispersed compared to before the construction.. But the effect was not so big and it suggests that other scenarios which make the population and economy dispersed more.

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Increased passengers’ bus waiting irritations at bus stops by bus facility types is one of the factors that decrease users’use intentions. Passengers’ waiting behavior at bus stops has not been discussed sufficiently so far although it should be one of the key factors of bus attractions. Using the behavior observation data, this study aims to identify the factors of the bus waiting irritation by analyzing the effect of bus facility types to passengers’ waiting behavior depending on the operation services and individual attributes. Analyzing the behavior observation acquired data revealed the differences of the bus waiting behavior in each bus facility type by the operation services and individual attributes. Also, conducting variance analysis to reveal the factors of bus waiting irritations. At the result, the factors of increasing and decreasing bus waiting irritations are bus facility types, the frequency of bus services and passengers’ information acquisition methods of bus.

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This research estimated the passengers’ benefit accrued by expressway expansion. An integrated travel demand model which is composed of mode choice, destination choice and trip generation model was developed in order to comprehensively assess the behavioral changes brought by expressway expansion. In addition, “travel time delay”was explicitly considered in the mode choice model as an indicator of travel time reliability. The result showed that the value of travel time reliability was around 40 times larger than that of travel time savings, and the amount of travel demands such as induced, transferred and shifted traffics would be too large to ignore even if the length of expressway expansion were relatively short distance. Also shown was that the passengers’ benefit attributed to those demand accounts for approximately half of overall benefit. These results indicate that the current evaluation method based on the road network assignment model with fixed demand might seriously underestimate the passengers’benefit accrued by expressway expansions and mislead the policy decision to postpone them.

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Color Pavement on road side belt that can be constructed even on narrow streets in residential areas has been increased in Japan. Although this traffic safety measure can be constructed early at low cost, it is necessary to repaint it regularly in order to maintain the effect as a traffic safety measure because color pavement often occurs to deteriorate over time. However, there is no clear criterion as to when to repaint color pavement, therefore, we have no choice but to decide the timing of repainting by subjective judgment rather than objective one. We examined criteria to repaint color pavement from a driver's point of view. Specifically, eye mark recorder and driving simulator were used to examine the influence of degradation of color pavement on the driver's gaze behavior and on driver consciousness. Based on these results, it is clarified that "peeling rate 40%" can be one criterion for repainting color pavement.

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In the long-term management for bridges, it is necessary to consider not only repair cost but also road user cost caused by repair work. In this paper, it aims to propose an evaluation method of long-term management for multiple bridges considering road user cost. For the purpose, we evaluate the management scenarios for multiple bridges with life cycle cost, which is estimated with the combined method of bridge deterioration model and traffic assignment model. As a result, we can clearly recognize that road user cost is important for management, since it amounts almost half of the repair cost. Furthermore, the preventive management scenario is superior to the other management scenarios without the specific case which the bridges degrade slowly. In addition, it is confirmed that the preventive management scenario is more suitable as a long-term management plan for bridges than the post management scenario, though the repair cost and road user cost is estimated larger only at the initial period.

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Vehicle-following behavior in a passing lane was analyzed based on vehicle trajectories estimated by video images synchronously acquired by eleven cameras that were installed for four days at the Yamato sag outbound section of Tomei motorway. Discriminant criteria of lead vehicles of platoons were formulated based on closed-loop behaviors of vehicles on time-headway and relative-speed planes. The parameter values of a vehicle-following model with relative-acceleration as a differential term were optimized for root-mean-square errors of the estimated positions of vehicles. The model was applied with optimized parameters to the simulation of leading uncongested and congested vehicle-platoons. The model successfully demonstrated the advantages of reproducibility to the existing models. Vehicle-following behavior of congested platoons was simulated for four days after the lead vehicles had been replaced by those of leading uncongested platoons. The results reconfirmed a possibility that congestion phenomena were influenced by the reduction in the velocity of the lead vehicles of the platoons at the upgrade section as well as their initial velocity.

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The purpose of this study is to examine the effect and its continuousness for the chokers installed serially in residential road having the two-way traffic in Oridukatamachi Inazawa-shi Aichi. Changes in traffic flow were investigated and analyzed before and at two points after improvement of the chokers’ road. As a result, the following findings were obtained. In a road section including the two chokers, both of the average traveling speed of vehicles after improvement have decreased compared to before improvement. A certain level of effect and its continuance on the chokers installed serially are recognized. However, there is a possibility that the effect of speed control decreases slightly with passage of years after improvement. One of the causes is the progress of the concession behavior at the time of passing the chokers in traffic vehicles. In addition, even if a short choker interval is provided, the traveling speed decreases only in a local range. It would be important to take measures in a comprehensive viewpoint based on the road conditions in the longitudinal direction of each choker.

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