Latent classes of daily mobility patterns: the relationship with attitudes towards modes

Transportation - Active modes (i.e. walking and cycling) have received significant attention by governments worldwide, due to the benefits related to the use of these modes. Consequently,...     

Robustness to Speed of 4WS Vehicles for Yaw and Lateral Dynamics

This paper addresses the issue of robustness and closed loop performance of four wheel steering (4WS) vehicles for yaw and lateral maneuvers for fixed and non-fixed speeds. A feedback structure derived from the plant inverse dynamic, such that the vehicle 2×2 matrix transfer function is robust to speed, is proposed. The efficiency of the proposed structure depends on the actuator's bandwidth and non-linearities, and on the sensor delay. A design example which shows how to implement the proposed algorithm in highly uncertain vehicles, subject to actuator bandwidth limitations and sensor delay, is provided.     

Integrated modeling of urban hierarchy and transportation network planning

A major problem addressed during the preparation of spatial development plans relates to the accessibility to facilities where services of general interest such as education, health care, public safety, and justice are offered to the population. In this context, planners typically aim at redefining the level of hierarchy to assign to the urban centers of the region under study (with a class of facilities associated with each level of hierarchy) and redesigning the region’s transportation network. Traditionally, these two subjects – urban hierarchy and transportation network planning – have been addressed separately in the scientific literature. This paper presents an optimization model that simultaneously determines which urban centers and which network links should be promoted to a new level of hierarchy so as to maximize accessibility to all classes of facilities. The possible usefulness of the model for solving real-world problems of integrated urban hierarchy and transportation network planning is illustrated through an application to the Centro Region of Portugal.     

Simulation of wind-driven circulation in the Gulf of Elat (Aqaba)

The Princeton Ocean Model (POM) has been used to investigate the wind-driven circulation in the stratified long and narrow Gulf of Elat (Aqaba). Our results indicate that the circulation consists of a series of gyres aligned along the main axis of the basin, and that their size and location are strongly affected by the shoreline and, to a lesser extent, by the hydrography. The seasonality in both the flow and the free surface height (FSH) at any specific station are caused mainly by the strong seasonality in the hydrography — the FSH and the magnitude of the currents above the thermocline are inversely related to the thickness of the upper layer. The seasonality in the flow is also manifested in the location and diameter of the gyres. This seasonal change in the gyres' diameter and location might provide an explanation for the current reversal observed at the northern tip of the western boundary during the month of February.     

How does travel satisfaction sum up? An exploratory analysis in decomposing the door-to-door experience for multimodal trips

Transportation - Understanding how satisfaction with individual trip legs aggregates to the overall travel experience for different types of trips will enable the identification of the trip legs...     

A hybrid scheme for real‐time prediction of bus trajectories

The uncertainty associated with public transport services can be partially counteracted by developing real‐time models to predict downstream service conditions. In this study, a hybrid approach for predicting bus trajectories by integrating multiple predictors is proposed. The prediction model combines schedule, instantaneous and historical data. The contribution of each predictor as well as values of respective parameters is estimated by minimizing the prediction error using a linear regression heuristic. The hybrid method was applied to five bus routes in Stockholm, Sweden, and Brisbane, Australia. The results indicate that the hybrid method consistently outperforms the timetable and delay conservation prediction method for different route layouts, passenger demands and operation practices. Model validation confirms model transferability and real‐time applicability. Generating more accurate predictions can help service users adjust their travel plans and service providers to deploy proactive management and control strategies to mitigate the negative effects of service disturbances. Copyright © 2017 John Wiley & Sons, Ltd.     

Relocating shared automated vehicles under parking constraints: assessing the impact of different strategies for on-street parking

Transportation - With shared mobility services becoming increasingly popular and vehicle automation technology advancing fast, there is an increasing interest in analysing the impacts of...     

Can passenger flow distribution be estimated solely based on network properties in public transport systems?

Transportation - We present a pioneering investigation into the relation between passenger flow distribution and network properties in public transport systems. The methodology is designed in a...     

What are the determinants of the willingness to share rides in pooled on-demand services?

Transportation - Simulation studies suggest that pooled on-demand services (also referred to as Demand Responsive Transport, ridesharing, shared ride-hailing or shared ridesourcing services) have...     

Real-Time Bus Arrival Information System: An Empirical Evaluation

The provision of real-time information concerning bus arrival times could potentially reduce the uncertainty associated with public transport trips and improve the overall level of service. In addition, real-time predictions might enable operators to apply proactive control strategies. Even though considerable research efforts were devoted to the development of bus arrival prediction schemes, there is a lack of knowledge on the performance of real-world operational systems. This article aims to investigate the performance of a commonly deployed real-time information generation scheme. A conventionally used scheme is implemented and evaluated based on an empirical analysis. Performance metrics concerning the prediction error accuracy and reliability and their impact on expected waiting time were formulated from both passengers’ and operators’ perspectives. The real-time information generator was applied on the trunk line network in Stockholm, Sweden. The accuracy and reliability of the prediction scheme was analyzed by comparing the generated predictions against vehicle positioning data. This scheme was found to systematically underestimate the remaining waiting time by 6.2% on average. The provision of real-time information yields a waiting time estimate that is more than twice as close to the actual waiting times than the timetable. This difference in waiting time expectations is equivalent to 30% of the average waiting time.