Highway Capacity Manual改訂の動向--テイラ-教授の講演より

To promote wide-spread adoption of Electric Vehicles (EVs), various government organizations are providing subsidies for installation of charging infrastructure in various countries and encouraging the adoption of Electric Buses (EV Buses) for city transportation. Though EV Buses are environment-friendly, the buses as well as the charging facilities including quick chargers and rechargeable Stationary Storage Batteries (SSBs) are expensive. Therefore, it is expected that in near future some of the city buses of a route will be replaced with EV Buses, and SSBs along with grid power will be used to charge these buses. In that situation, proper operation and charging scheduling of the EV Buses will be needed. In this paper, the authors propose a k-Greedy Algorithm-based approach for this task. They perform simulations by using the real bus diagram data of four bus routes of a city bus route network in Japan and evaluate the algorithm from various perspectives. Our simulation results suggest that the k-Greedy Algorithm can maximize the travel distance of the EV Buses, which contributes to reducing fuel cost and CO2 emission for a bus operator.

Operation and Charging Scheduling of Electric Buses in a City Bus Route Network

Pedestrian road crossings have become a major issue in road traffic flow, especially in urban areas where there is no controll for pedestrian road crossings. Pedestrian road crossing behaviour is a serious threat to pedestrians at uncontrolled midblock crossing locations in the mixed traffic conditions. Due to increase in motor vehicle growth there is an increase in the regulation of motor vehicles only and the regulation of pedestrian is completely neglected. This increases the uncontrolled road crossing behaviour of pedestrian. The main motivation of this study is to investigate the pedestrian road crossing behaviour at the uncontrolled midblock location in India under mixed traffic condition. Pedestrian road crossing behaviour at uncontrolled midblock has been modeled by the size of vehicular gaps accepted by pedestrian using multiple linear regression (MLR) technique. Also choice model has been developed to capture the decision making process of pedestrian i.e., accepted or rejected vehicular gaps based on the discrete choice theory. Suitable study stretch, which a four lane divided urban arterial in Hyderabad, India, was selected for data collection. The collected data consists of 4198 gap data points which include both accepted and rejected vehicular gaps. Pedestrians’ road crossing behaviour has been explained in terms of minimum gap acceptance value by using a rolling gap (pedestrian roll over the small vehicular gaps). It has also been explained by the binary logit model with the help of vehicular gap size, frequency of attempt and rolling gap. The study concludes that the pedestrian behavioural characteristics like the rolling gap, driver yielding behaviour and frequency of attempt plays an important role in pedestrian uncontrolled road crossing. These inferences are helpful for pedestrian facility design and controlling pedestrian safety issues at uncontrolled crossings.

Modelling pedestrian road crossing behaviour under mixed traffic condition

Exploring impacts of countdown timers on traffic operations and driver behavior at a signalized intersection in Bangkok

Impact of Countdown Timer on Driving Maneuvers after the Yellow Onset at Signalized Intersections: An Empirical Study in Changsha, China

Intersections are bottleneck in the highway networks and critical determinant of system's capacity and safety. Recently, several countdown timers had been installed at intersections in Kuala Lumpur and some other cities in Malaysia. The function of these timers is to aid drivers to judge the amount of time left for them to get the green signal for moving (starting) their vehicles as well as the amount of green time available for them to proceed across the intersection or to stop safely before the signal turns red. This advance information is supposed to help drivers in reducing their initial delay, especially for the first few vehicles and improving safety level. In the present research six intersections, three with count down timers and three with no-count down timer are analyzed to study the effect of count down timer on driver behavior, intersection approach headway and safety levels. The study suggests that countdown timer has got little effect on initial delay but the effect on headway is significant. The violation of traffic light by the drivers for countdown and normal signal is also compared.

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The Effect of Digital Count-Down Display on Signalized Junction Performance

In this paper we present an optimization model for bus scheduling. This model constitutes one of the three major components of a solution approach for solving the transit network design problem. The problem of scheduling can be defined in the following general terms: Given the origin destination matrix for the bus trips for design period, the underlying bus network characterized by the overlapping routes, how optimally to allocate the buses among these routes? The bus scheduling problem is solved in two levels. In the first level, minimum frequency of buses required on each route, with the guarantee of load feasibility, is determined by considering each route individually. In the second level, the fleet size of first level is taken as upper bound and fleet size is again minimized by considering all routes together and using GAs. The model is applied to a real network, and results are presented.

A genetic algorithm based bus scheduling model for transit network

Intersections are bottleneck in the urban highway network and critical determinant of system's capacity, efficiency and safety. Recently, several countdown timers had been installed at intersections in Kuala Lumpur and some other cities in Malaysia. The function of these timers is to aid drivers to judge the amount of time left for them to get the green signal for starting their vehicles. This advance information is supposed to help drivers in reducing their initial delay especially for the first few vehicles. In the present research one intersection in a non-CBD area has been analyzed to study the effect of count down timer on driver behavior and intersection approach capacity. The data is collected at the same intersection before and after the installation of count down signal in order to exclusively study the effect of timer, keeping other factors the same. The intersection approach capacity of countdown signal is compared with normal signal and other standards. The study suggests that countdown timer has got very little effect on capacity. Though there is large variation in capacity values for different cycles, but the average capacity values for both countdown and normal signal approach are very close to US Highway Capacity Manual values. For the safety level comparison of conventional and timer signalized intersections the data for red light running is analyzed and results are reported.

Traffic flow analysis of digital count down signalized urban intersection

Pedestrians are vulnerable road user. In developing countries the drivers' attitude towards pedestrians is quite different than from developed ones. In this research we present the findings of interaction between motorists and pedestrians at unsignalised zebra crossing facilities in a University Campus in Malaysia. It has been observed that the pedestrians have great difficulty in crossing as most of the drivers don't care for the waiting pedestrians. The pedestrians have to wait for a significantly long time before finding someone who is willing to stop for them to allow them to cross or wait until there are no more vehicles close enough (large headways). This phenomenon may probably be due to the misunderstanding on the rule of the right of way in such a situation or it could also be due to the attitude of the motorists themselves that they are not willing to stop because they would be losing travel time whereas the pedestrian can afford to wait.

Motorists and pedestrian interaction at unsignalised pedestrian crossing

Pedestrian safety at signalized intersections is a major cause of concern all over the world. Properly marked crosswalk enhances the safety of pedestrians as it is a well recognized crossing location by drivers. However a large number of accidents are reported at intersections predominantly due to the violation behavior of pedestrians. This study aims at understanding the crosswalk utilization behavior of pedestrians at urban signalized intersections. Data was collected through video recording and a questionnaire survey. Significant variables were identified and modelled using binomial logistic regression. Pedestrian personal level factors were found to significantly affect crosswalk compliance. Discrepancies were identified between perception and reality, suggesting that variation exists between what people say and what they practice in reality. The findings from this study suggest that a perception based study may not be as reliable as an observational study. The findings have both theoretical as well as practical implications and would certainly help the policy makers and designers in enhanced understanding of pedestrian behavior at urban signalized intersections. 

Farhan Ahmad Kidwai

Papers

The Effect of Digital Count-Down Display on Signalized Junction Performance

A genetic algorithm based bus scheduling model for transit network

Traffic flow analysis of digital count down signalized urban intersection

Motorists and pedestrian interaction at unsignalised pedestrian crossing

Crosswalk Utilization by Pedestrian: Perception versus Reality - Case Study of New Delhi