On Transport Service Selection in Intermodal Rail/Road Distribution Networks

Intermodal rail/road freight transport constitutes an alternative to long-haul road transport for the distribution of large volumes of goods. The paper introduces the intermodal transportation problem for the tactical planning of mode and service selection. In rail mode, shippers either book train capacity on a per-unit basis or charter block trains completely. Road mode is used for short-distance haulage to intermodal terminals and for direct shipments to customers. We analyze the competition of road and intermodal transportation with regard to freight consolidation and service cost on a model basis. The approach is applied to a distribution system of an industrial company serving customers in eastern Europe. The case study investigates the impact of transport cost and consolidation on the optimal modal split.

Study of Military Air Transport Service. Hearings before a special subcommittee, Eighty-fifth Congress, second session. May 19, June 12-13, 1958.

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La percepción de la calidad en el sector de la mensajería urgente

[ES] Esta investigación muestra como, en el servicio de transporte urgente y mensajería, el operador público «Correos» es percibido con una calidad inferior a varios de sus competidores más cercanos: Seur, MRW y Nacex. A pesar de los esfuerzos realizados por esta entidad pública en la mejora de la calidad del servicio, éstos no se ven reflejados en las evaluaciones de los consumidores, al menos al mismo nivel que sus competidores. Estos resultados han sido obtenidos tras la utilización de diferentes metodologías, como la regresión ordinal, la comparación entre grupos o los modelos multinivel. Asimismo, diversas propuestas para futuras investigaciones son comentadas al final del estudio.

Evaluating the transport impacts of transit oriented developments (TODS)

Sustainable transport has become a necessity instead of an option, to address the problems of congestion and urban sprawl, whose effects include increased trip lengths and travel time. A more sustainable form of development, known as Transit Oriented Development (TOD) is presumed to offer sustainable travel choices with reduced need to travel to access daily destinations, by providing a mixture of land uses together with good quality of public transport service, infrastructure for walking and cycling. However, performance assessment of these developments with respect to travel characteristics of their inhabitants is required. This research proposes a five step methodology for evaluating the transport impacts of TODs. The steps for TOD evaluation include pre–TOD assessment, traffic and travel data collection, determination of traffic impacts, determination of travel impacts, and drawing outcomes. Typically, TODs are comprised of various land uses; hence have various types of users. Assessment of characteristics of all user groups is essential for obtaining an accurate picture of transport impacts. A case study TOD, Kelvin Grove Urban Village (KGUV), located 2km of north west of the Brisbane central business district in Australia was selected for implementing the proposed methodology and to evaluate the transport impacts of a TOD from an Australian perspective. The outcomes of this analysis indicated that KGUV generated 27 to 48 percent less traffic compared to standard published rates specified for homogeneous uses. Further, all user groups of KGUV used more sustainable modes of transport compared to regional and similarly located suburban users, with higher trip length for shopping and education trips. Although the results from this case study development support the transport claims of reduced traffic generation and sustainable travel choices by way of TODs, further investigation is required, considering different styles, scales and locations of TODs. The proposed methodology may be further refined by using results from new TODs and a framework for TOD evaluation may be developed.

Influence of service loading and the resulting micro-cracks on chloride resistance of concrete

Chloride-induced corrosion of steel in reinforced concrete structures is one of the main problems affecting their durability, but most previous research projects and case studies have focused on concretes without cracks or not subjected to any structural load. Although it has been recognised that structural cracks do influence the chloride transport and chloride induced corrosion in reinforced concrete structures, there is little published work on the influence of micro-cracks due to service loads on these properties. Therefore the effect of micro-cracks caused by loading on chloride transport into concrete was studied. Four different stress levels (0%, 25%, 50% and 75% of the stress at ultimate load – fu) were applied to 100 mm diameter concrete discs and chloride migration was measured using a bespoke test setup based on the NT BUILD 492 test. The effects of replacing Portland cement CEMI by ground granulated blast-furnace slag (GGBS), pulverised fuel ash (PFA) and silica fume (SF) on chloride transport in concrete under sustained loading were studied. The results have indicated that chloride migration coefficients changed little when the stress level was below 50% of the fu; however, it is desirable to keep concrete stress less than 25% fu if this is practical. The effect of removing the load on the change of chloride migration coefficient was also studied. A recovery of around 50% of the increased chloride migration coefficient was found in the case of concretes subjected to 75% of the fu when the load was removed.

ECLAC: thirty years of contributing to transport infrastructure institutionbuilding in Latin America and the Caribbean

This edition of the FAL Bulletin summarizes the principal contributions by ECLAC and its Infrastructure Services Unit to creating and strengthening transport service infrastructure institutions in Latin America and the Caribbean. The examination is based on a bibliography of key documents issued by ECLAC since it was founded, on studies conducted by the Infrastructure Services Unit and on FAL Bulletins from the past 15 years.

Providing Reliable Data Transport for Dynamic Event Sensing in Wireless Sensor Networks

In this paper, we propose a Loss Tolerant Reliable (LTR) data transport mechanism for dynamic Event Sensing (LTRES) in WSNs. In LTRES, a reliable event sensing requirement at the transport layer is dynamically determined by the sink. A distributed source rate adaptation mechanism is designed, incorporating a loss rate based lightweight congestion control mechanism, to regulate the data traffic injected into the network so that the reliability requirement can be satisfied. An equation based fair rate control algorithm is used to improve the fairness among the LTRES flows sharing the congestion path. The performance evaluations show that LTRES can provide LTR data transport service for multiple events with short convergence time, low lost rate and high overall bandwidth utilization.

The role of relational capabilities in developing the capacity for supply chain innovation

The purpose of this paper is to gain a better understanding of the types of relational capabilities supply chain participants develop to enable ongoing supply chain innovation capacity building that produces improved business outcomes. This is exploratory research using qualitative data gathered by using five interviews, with the Australian road freight industry as the context. Two key relational capabilities and the improvement of four key business outcomes were identified as being present in the interaction of freight transport service providers with members of their supply chain. The data also demonstrates that by entering into competence building relationships with customers and suppliers firms can build capabilities that will increase their capacity for supply chain innovation. Even in short term arm’s length relationships firms can acquire improved skills behaviours and practices that enhance their operation effectiveness and the efficiency of the supply chain relationships.

Conceptualising convenience : transportation practices and perceptions of inner-urban high density residents in Brisbane, Australia

High-density living in inner-urban areas has been promoted to encourage the use of more sustainable modes of travel to reduce greenhouse gas emissions. However, previous research presents mixed results on the relationship between living in proximity to transport systems and reduced car-dependency. This research examines inner-city residents’ transportation practices and perceptions, via 24 qualitative interviews with residents from high-density dwellings in inner-city Brisbane, Australia. Whilst participants consider public transport accessible and convenient, car use continues to be relied on for many journeys. Transportation choices are justified through complex definitions of convenience containing both utilitarian and psycho-social elements,with three key themes identified: time-efficiency, single versus multi-modal trips, and distance to and purpose of journey, as well as attitudinal, affective and symbolic elements related to transport mode use. Understanding conceptions of transport convenience held by different segments of the transport users market,alongside other factors strongly implicated in travel mode choice, can ensure targeted improvements in sustainable transport service levels and infrastructure as well as information service provision and behavioural change campaigns.

Using GIS to visualise and evaluate student travel behaviour

Using GIS to evaluate travel behaviour is an important technique to increase our understanding of the relationship between accessibility and transport demand. In this paper, the activity space concept was used to identify the nature of participation in activities (or lack of it) amongst a group of students using a 2 day travel-activity diary. Three different indicators such as the number of unique locations visited, average daily distance travelled, and average daily activity duration were used to measure the size of activity spaces. These indicators reflect levels of accessibility, personal mobility, and the extent of participation respectively. Multiple regression analyses were used to assess the impacts of students socio-economic status and the spatial characteristics of home location. Although no differences were found in the levels of accessibility and the extent of participation measures, home location with respect to a demand responsive transport (DRT) service was found to be the most important determinant of their mobility patterns. Despite being able to travel longer distances, students who live outside of the DRT service area were found to be temporally excluded from some opportunities. Student activity spaces were also visualised within a GIS environment and a spatial analysis was conducted to underpin the evaluation of the performance of the DRT. This approach was also used to identify the activity spaces of individuals that are geographically excluded from the service. Evaluation of these results indicated that although the service currently covers areas of high demand, 90% of the activity spaces remained un-served by the DRT service. Using this data six new routes were designed to meet the coverage goal of public transport based on a measure of network impedance based on inverse activity density. Following assessment of public transport service coverage, the study was extended using a Spatial Multi Criteria Evaluation (SMCE) technique to assess the effect of service provision on patronage.

Modal choice between air and rail : a social efficiency benchmarking analysis that considers CO2 emissions

The problem of modal choice between rail and air arises as public awareness of carbon dioxide (CO2) emissions by the transportation sector rises. In this paper, we answer this question quantitatively by performing an efficiency benchmarking analysis that takes into account life-cycle CO2 emission due to transport service provision. The paper employs nonparametric efficiency estimation methods, namely a slacks-based inefficiency measure, as well as a more conventional directional distance function approach. We apply them to a panel data set for three major railway companies and the aviation sector in Japan for the period from 1999 to 2007. Results shows that, contrary to the common argument, air transport can still be more socially efficient than rail transport, even when the environmental load due to CO2 emission is incorporated. This is due to the aviation sector's extremely low user cost, measured in terms of in-vehicle time. In other words, aviation is a necessary transportation mode for those with a very high willingness to pay for their time.

Technology-mediated tools for shaping experiences in urban commuter trains

This thesis presents the results of a study into ways that technology can be appropriated and designed to support urban rail commuters in their daily journeys. The study evaluated a mobile application prototype deployed along the Brisbane passenger rail network. This prototype was designed to support social interaction between passengers sharing the same trains. This thesis provides a step forward in showing the relevance of increasingly creating solutions that contribute to a more enjoyable and attractive public transport service.