Correlates of bicycling trip flows in Hamilton,Ontario: fastest,quietest, or balanced routes?

Transportation - Bicycling is an increasingly popular mode of travel in Canadian urban areas, like the Greater Toronto and Hamilton Area (GTHA). While trip origins and destinations can be inferred...     

Trip generation of vulnerable populations in three Canadian cities: a spatial ordered probit approach

This paper provides an analysis of trip generation of three vulnerable groups: single-parent families, low income households, and the elderly. It compares the mobility of these groups to that of the general population in three Canadian urban areas of Hamilton, Montreal and Toronto, based on data from large-sample metropolitan transport surveys. An ordered probit model with spatially expanded coefficients is used for the analysis. Spatial expansion shows that there are spatial mobility trends for elderly populations and low-income populations even after socio-economic attributes are accounted for. Such spatial differences are not generally found for single parent families. This novel spatial analysis provides clues as to where vulnerable populations may experience greater degrees of social exclusion. It provides information to help prioritize transportation infrastructure projects or other social programs to take into account the needs of vulnerable populations with the lowest levels of mobility.     

Review and assessment of the nested logit model

The popular hierarchical or nested logit model that has been the recent source of heated discussions in the literature is reviewed and critically examined. The fundamental underpinnings of the model are first presented in a concise and easy-to-understand fashion and then used to assess each controversy in turn. Monte Carlo simulation is also used to examine some problems that are not possible to address by just resorting to the theory. The main conclusion is that all the model hypotheses are both essential and unambiguous and should not be ignored for a correct use of the model in practice.     

The impact of high-speed technology on railway demand

This paper estimates a passenger railway demand function to analyse effects arising from the introduction and use of high-speed technologies. The paper reports estimates of demand elasticities with respect to price, income, quality of service and a range of exogenous characteristics. The results show that travel time savings from conventional high-speed technology have a larger impact on passenger demand than tilting train technology. The introduction of conventional high-speed technology is associated with an 8% increase in passenger railway demand. Increasing the use of either type of high-speed technology appears to induce small positive effects on demand beyond those obtained from usual traffic density increases on non-high-speed existing technology.

Transantiago: A tale of two cities

The Chilean government decided to modernize Santiago's entire public transport system, integrating the underground and the private bus networks based on a structure of trunk and feeder services, and a fare-payment by touchless smart card. The new, integrated transit system, known as Transantiago, very soon ran into serious problems that alienated much of its user base and significantly lowered the government's approval ratings. This paper recounts how Transantiago was planned and designed and then discusses its evolution after implementation. It concludes with suggestions for the Transantiago authorities and lessons to be learned from this traumatic process.     

A selection method of offshore production systems considering uncertainties

Journal of Marine Science and Technology - The development of an offshore deepwater oilfield is a complex and risky task. One core problem in this project is the selection of a production system...     

What Curriculum for Mobility and Transport Studies? A Critical Exploration

To understand the complex meanings of mobility and to engage in transport planning and management processes, a variety of disciplines, skills, and tools are potentially useful. Universities have a limited amount of time and resources to train future professionals though. This poses a problem: where should the teaching priorities be? By means of a web-survey, this study has asked academics based at a number of universities what the disciplines, skills, and tools that — according to their personal viewpoints — are the most relevant for practitioners in the mobility and transport sector. The respondents generally support curricula that facilitate a holistic, non-specialised, understanding of mobility and transport issues.     

URANS and DES analysis for a Wigley hull at extreme drift angles

Vortical structures and associated instabilities for flows around the Wigley hull for a wide range of drift angles (10° ≤ α ≤ 60°) with free surface are identified and analyzed. Quantitative verification and validation are conducted on three systematically refined grids with comparison to the experimental data for α = 10°. Analysis of the flow pattern shows a strong correlation between the vortical structures and free-surface wave elevation. For α = 10° and 30°, the flows remain steady and vortices are generated at the keel and fore and aft perpendiculars of the hull. The strength and complexity of these vortices increase with increasing α. At α = 45°, flow becomes unsteady without any significant change in the main flow pattern. At α = 60°, a complex and unsteady flow field on the leeward side of the hull is formed with a large recirculation region from the aft to the fore end, which prevents the flow coming from below the keel from moving up and generating the keel vortices observed at lower drift angles. Karman-like and helical instabilities are analyzed. The effect of Froude number is more apparent for large than for small drift angles.     

Simulation of turbulent effective wakes for propellers in off-design conditions by a correction factor approach

Journal of Marine Science and Technology - This paper presents a procedure for the estimation of propeller effective wakes in oblique flows. It shows how a recently developed method for controlling...     

A method for solving the multi‐objective transit frequency optimization problem

Frequency setting takes place at the strategic and tactical planning stages of public transportation systems. The problem consists in determining the time interval between subsequent vehicles for a given set of lines, taking into account interests of users and operators. The result of this stage is considered as input at the operational level. In general, the problem faced by planners is how to distribute a given fleet of buses among a set of given lines. The corresponding decisions determine the frequency of each line, which impacts directly on the waiting time of the users and operator costs. In this work, we consider frequency setting as the problem of minimizing simultaneously users' total travel time and fleet size, which represents the interest of operators. There is a trade‐off between these two measures; therefore, we face a multi‐objective problem. We extend an existing single‐objective formulation to account explicitly for this trade‐off, and propose a Tabu Search solving method to handle efficiently this multi‐objective variant of the problem. The proposed methodology is then applied to a real medium‐sized problem instance, using data of Puerto Montt, Chile. We consider two data sets corresponding to morning‐peak and off‐peak periods. The results obtained show that the proposed methodology is able to improve the current solution in terms of total travel time and fleet size. In addition, the proposed method is able to efficiently suggest (in computational terms) different trade‐off solutions regarding the conflicting objectives of users and operators. Copyright © 2017 John Wiley & Sons, Ltd.