Employment status and commute distance of Canadians with disabilities

Alleviating the disability challenges experienced by people with impairments is increasingly seen as an important step towards building more inclusive societies. The very definition of disability has evolved to shift the burden from people with impairments to perform at “normal” competency levels and towards a fuller recognition of the ways that society can either build or tear down barriers that hinder their full participation in society. The objective of this paper is to investigate the factors that act as facilitators or barriers to participation by people with impairments. Specifically, the study is conducted within the context of employment status and commute distance, two outcomes indicative of the ability of individuals with impairments to engage society. Analysis is based on Canada’s 2006 Participation and Activity Limitation Survey, a post-censal survey that collects information on various aspects of disabilities for a representative sample of Canadian society. The results, based on a probit model for employment status and a regression model for commute distance, provide insights into the personal, economic, and living space factors that affect the probability of being employed and traveling longer distances.     

Nonlinear Design Approach to Four-Wheel-Steering Systems Using Neural Networks

Four-wheel-steering (4WS) systems have been studied and developed with remarkable success from the viewpoint of vehicle dynamics. Most of the control methods require a linearized bicycle model of the actual vehicle system which is however strongly influenced by tire nonlinearity. This paper proposes a new method to design the 4WS system taking into account the nonlinear characteristics of tires and suspensions. For this purpose integration of artificial neural network and linear control theory is introduced for the identification and control of a nonlinear vehicle model structured using a software for multi-body dynamic analysis (ADAMS). This model takes into account the nonlinear characteristics of actual vehicles with tires modeled by “magic formula“. The results of computer simulations show that the proposed nonlinear approach is efficient in improving the handling and stability of vehicles.     

The contribution of total suspended solids to the Bay of Biscay by Cantabrian Rivers (northern coast of the Iberian Peninsula)

Information of suspended sediments fluxes of small rivers to the coastal zone is sparse, and this is particularly so for the Iberian Rivers. To help address this shortage of information, the relationship between fluvial discharge and total suspended solids (TSS) for the main 28 Cantabrian Rivers using data from 22 years monitoring by the COCA network has been analysed, and their particulate material fluxes to the Bay of Biscay coasts have been quantified. The Cantabrian Fluvial System (drainage basin area of 20,333 km²) may be considered as a quasi-homogeneous fluvial system with an average discharge of 561 m^− 3 s^− 1 and average loads of 35 kg_TSS s^− 1 with rivers showing similar average yields of 56 t km^− 2 a^− 1. The average TSS contribution is 1.2 ± 0.2 10⁹ kg a^− 1. This seaward flux of sediment is dispersed along the entire North Iberian coast and is rather modest (25% of the total supply) in comparison with the output from the French Rivers to the Bay of Biscay. The TSS loads of Cantabrian Rivers indicate they are similar to world upland rivers and those of other parts of Northern Europe according to Milliman and Syvistki [Milliman and Syvistki, 1992. Geomorphic/tectonic control of sediment discharge to the ocean: the importance of small mountainous rivers. Journal of Geology, 100: 525–544] and Milliman [Milliman, 2001. Delivery and fate of fluvial water and sediment to the sea: a marine geologist's view of European rivers. Scientia Marina, 65: 121–132]. Although their TSS flux is practically negligible (13,000 times lower) when compared to the world average flux, they provide a good example of the role of small Atlantic temperate rivers.     

A fuzzy method for predicting the demand for rail freight transportation

The demand for rail freight transportation is a continuously changing process over space and time and is affected by many quantitative and qualitative factors. In order to develop a more rational transport planning process to be followed by railway organizations, there is a need to accurately forecast freight demand under a dynamic and uncertain environment. In conventional linear regression analysis, the deviations between the observed and the estimated values are supposed to be due to observation errors. In this paper, taking a different perspective, these deviations are regarded as the fuzziness of the system's structure. The details of fuzzy linear regression method are put forward and discussed in the paper. Based on an analyzes of the characteristics of the rail transportation problem, the proposed model was successfully applied to a real example from China. The results of that application are also presented here.     

Integrated Environmental Modeling and Assessment of Coastal Ecosystems: Application for Aquaculture Management

This article presents an approach that couples coastal ecosystem modeling with integrated environmental assessment methodologies to support coastal management. The focus is to support the development of an ecosystem approach to aquaculture management including interactions with watershed substance loading. A Chinese bay, with intense aquaculture and multiple catchment uses, and where significant modeling efforts were undertaken is used as a case study. The ecosystem model developed for this bay is used to run scenarios that test the local management strategy for nutrient reduction. The corresponding ecological and economic impacts of the managers’ scenarios are analyzed by means of the Differential Drivers-Pressure-State-Impact-Response (ΔDPSIR) analysis. Emphasis is given to the analysis of the eutrophication process in the bay including present eutrophic condition and the expected changes due to the simulated scenarios. For this purpose, the Assessment of Estuarine Trophic Status (ASSETS) screening model is a valuable tool to interpret and classify the data and model outputs regarding eutrophication condition and to evaluate the manageable level of the nutrient loading entering in the bay.     

A tour-based model of travel mode choice

This paper presents a new tour-based mode choice model. The model is agent-based: both households and individuals are modelled within an object-oriented, microsimulation framework. The model is household-based in that inter-personal household constraints on vehicle usage are modelled, and the auto passenger mode is modelled as a joint decision between the driver and the passenger(s) to ride-share. Decisions are modelled using a random utility framework. Utility signals are used to communicate preferences among the agents and to make trade-offs among competing demands. Each person is assumed to choose the best combination of modes available to execute each tour, subject to auto availability constraints that are determined at the household level. The households allocations of resources (i.e., cars to drivers and drivers to ride-sharing passengers) are based on maximizing overall household utility, subject to current household resource levels. The model is activity-based: it is designed for integration within a household-based activity scheduling microsimulator. The model is both chain-based and trip-based. It is trip-based in that the ultimate output of the model is a chosen, feasible travel mode for each trip in the simulation. These trip modes are, however, determined through a chain-based analysis. A key organizing principle in the model is that if a car is to be used on a tour, it must be used for the entire chain, since the car must be returned home at the end of the tour. No such constraint, however, exists with respect to other modes such as walk and transit. The paper presents the full conceptual model and estimation results for an initial empirical prototype. Because of the complex nature of the model decision structure, choice probabilities are simulated from direct generation of random utilities rather than through an analytical probability expression.     

Managing a smart bicycle system when demand outstrips supply: the case of the university community in Seville

Of the many public initiatives used to promote the use of bicycles in the urban environment, the one that has achieved the most spectacular results in a short period of time is the public bicycle hire system. The experience of Seville is one of the most successful internationally, where 6.6 % of mechanised trips were being made by bicycle within 30 months. This paper analyses this experience in the university community, which represents one-third of system users. We conclude that the people who are most satisfied with the system are those who use it for leisure and recreation activities, non-residents of the city, more environmentally aware people and those who have no alternative mode of transportation. Their satisfaction is also closely linked to their appreciation of the bicycles’ level of comfort, the ease with which users can hire bicycles and return them and the small amount of paperwork involved required to sign up for the system. However, user appreciation has fallen over time because the system’s rapid success has caused it to become overloaded. This experience therefore provides one main lesson: the system’s success can result in eventual difficulties.     

Using Bus Rapid Transit to Mitigate Emissions of CO2 from Transport

Abstract

This article investigates the role of bus rapid transit as a tool for mitigation of transport‐related carbon dioxide (CO₂) emissions. We analyse a Quality Bus Corridor (QBC) implemented in Dublin, Ireland, in 1999 and estimate CO₂ emissions associated with differing levels of bus priority for the period 1998–2003 and for the Kyoto commitment period (2008–12). Associated monetary values are established using CO₂ prices from the European Union Emissions Trading Scheme. We find that, in the absence of a QBC, peak‐time emissions for our sample population would have been 50% higher than in the factual scenario. For the Kyoto commitment period, we find the median value of the policy implementation to be in the region of [euro]650 000.     

Modelling major traffic incident impacts and estimation of their associated costs

Network area-wide impacts due to major traffic incidents can be assessed using a microsimulation approach. A VISSIM microsimulation model for a motorway network has been developed and is used to quantify impacts of a major incident in terms of associated costs. The modelled results reveal that a 65% capacity reduction results in 36% more incident-induced delay when compared with the application of a 50% capacity reduction assumption for a two-hour incident clearance duration that blocked one lane of a two-lane motorway. Additionally, an incident which caused a full blockage incurred 40 times more associated impact costs when compared with a major incident which caused a one lane blockage. A 23% cost saving can be achieved by clearing one lane of a fully blocked two-hour major traffic incident after 90 minutes, while a 37% cost saving can be achieved by clearing all blockages after 90 minutes.     

A model system for the ex-ante assessment of city logistics measures

This paper proposes a model system developed in order to support ex-ante assessment of city logistics measures. The model system allows us to simulate the choices of each decision-maker involved in the urban freight transport and logistics and to investigate how the policies and the following measures can influence her/his choices.The model system is an open architecture and consists of two levels: commodity and vehicle. The commodity level allows us to analyse the attraction and acquisition movements taking into account the effects due to city logistics policy implementation affecting the end-consumer and retailer/wholesaler/producer (restocker) choices. The freight sold in each urban shop (or in general urban business) is estimated starting from consumption demand and, then, the restocker’s choices for restocking are analysed in depth. The vehicle level focuses on the restocking process and the links between retailer and wholesaler/producer operating in the study area. This level allows us to investigate the impacts of implementing city logistics measures on journey time, timing and path used for restocking the urban retail businesses.