Vol 12 No 3 (2012)
Vol 12 No 3 (2012)
Articles
-
-
-
In freight distribution services a required quality level may have a relevant effect on transportation costs. For this reason an evaluation tool is useful to compare different service settings and support the decision, on the base of quantitative indicators. This paper proposes a method for cost evaluation in this context and presents an application to a case study concerning a freight distribution service, which operates on a wide road network having a city centre, a peripheral urban area and a peri-urban rural zone. A simulation method is proposed to obtain real-life scenarios in order to test the method and its indicators. The performance of each indicator has been evaluated in an experimental context to produce realistic test cases, using a trip planning tool and a demand generator. First, the behaviour of the indicators is analysed with regard to the time windows width planned for the service. Then, their ability in estimating the total transportation cost to satisfy all the requests, under different time period profiles, is shown. The results confirm the ability of the set of indicators to predict with a good approximation the transportation costs and therefore to be used in supporting the service quality planning decisions.
In freight distribution services a required quality level may have a relevant effect on transportation costs. For this reason an evaluation tool is useful to compare different service settings and support the decision, on the base of quantitative indicators. This paper proposes a method for cost evaluation in this context and presents an application to a case study concerning a freight distribution service, which operates on a wide road network having a city centre, a peripheral urban area and a peri-urban rural zone. A simulation method is proposed to obtain real-life scenarios in order to test the method and its indicators. The performance of each indicator has been evaluated in an experimental context to produce realistic test cases, using a trip planning tool and a demand generator. First, the behaviour of the indicators is analysed with regard to the time windows width planned for the service. Then, their ability in estimating the total transportation cost to satisfy all the...
In freight distribution services a required quality level may have a relevant effect on transportation costs. For this reason an evaluation tool is useful to compare different service settings and support the decision, on the base of quantitative indicators. This paper proposes a method for...
Francesco Deflorio, Jesus Gonzalez-Feliu, Guido Perboli, Roberto Tadei -
One of the critical concerns of axial analysis, a space syntax approach to capturing vehicular travel behavior emulating configurational properties of roadway structures, is the absence of the time-cost consideration while dealing with route-choice problems encountered in grid-like urban textures. This study shows that the time-cost parameter of travel can also be introduced into the syntax approach to capturing the route-choice decisions for the purpose of modeling vehicular movement networks with greater accuracy. Assuming that roadway units are trip-origins and trip-destinations and that they also act as connecting route segments among each other, a theoretical foundation has been proposed showing how the mobility characteristics of these units, in terms of the time-cost of travel, influence their accessibility measures or syntax integrations. These new roadway units are the unit segments, and their integrations are found to be better indicators of vehicular trip-makers’ route-choice decisions than axial integrations. Conclusions suggest that the unit-segment analysis of an urban grid captures the general behavior of vehicular flow by substantiating the fact that trip-makers tend to pick a specific set of roadway units that not only comprise the close connection between a triporigin and a trip-destination but also consume less time for travel.
One of the critical concerns of axial analysis, a space syntax approach to capturing vehicular travel behavior emulating configurational properties of roadway structures, is the absence of the time-cost consideration while dealing with route-choice problems encountered in grid-like urban textures. This study shows that the time-cost parameter of travel can also be introduced into the syntax approach to capturing the route-choice decisions for the purpose of modeling vehicular movement networks with greater accuracy. Assuming that roadway units are trip-origins and trip-destinations and that they also act as connecting route segments among each other, a theoretical foundation has been proposed showing how the mobility characteristics of these units, in terms of the time-cost of travel, influence their accessibility measures or syntax integrations. These new roadway units are the unit segments, and their integrations are found to be better indicators of vehicular trip-makers’...
One of the critical concerns of axial analysis, a space syntax approach to capturing vehicular travel behavior emulating configurational properties of roadway structures, is the absence of the time-cost consideration while dealing with route-choice problems encountered in grid-like urban...
Abhijit Paul -
Although the phenomenon of induced traffic has been theorized for more than 60 years and is now widely accepted among transport researchers, the traffic-generating effects of road capacity expansion are still often neglected in transport modelling. Such omission can lead to serious bias in the assessments of environmental impacts as well as the economic viability of proposed road projects, especially in situations where there is a latent demand for more road capacity. This has been illustrated in the present paper by an assessment of travel time savings, environmental impacts and the economic performance of a proposed road project in Copenhagen with and without short-term induced traffic included in the transport model. The available transport model was not able to include long-term induced traffic resulting from changes in land use and in the level of service of public transport. Even though the model calculations included only a part of the induced traffic, the difference in cost-benefit results compared to the model excluding all induced traffic was substantial. The results show lower travel time savings, more adverse environmental impacts and a considerably lower benefit-cost ratio when induced traffic is partly accounted for than when it is ignored. By exaggerating the economic benefits of road capacity increase and underestimating its negative effects, omission of induced traffic can result in overallocation of public money on road construction and correspondingly less focus on other ways of dealing with congestion and environmental problems in urban areas.
Although the phenomenon of induced traffic has been theorized for more than 60 years and is now widely accepted among transport researchers, the traffic-generating effects of road capacity expansion are still often neglected in transport modelling. Such omission can lead to serious bias in the assessments of environmental impacts as well as the economic viability of proposed road projects, especially in situations where there is a latent demand for more road capacity. This has been illustrated in the present paper by an assessment of travel time savings, environmental impacts and the economic performance of a proposed road project in Copenhagen with and without short-term induced traffic included in the transport model. The available transport model was not able to include long-term induced traffic resulting from changes in land use and in the level of service of public transport. Even though the model calculations included only a part of the induced traffic, the difference in...
Although the phenomenon of induced traffic has been theorized for more than 60 years and is now widely accepted among transport researchers, the traffic-generating effects of road capacity expansion are still often neglected in transport modelling. Such omission can lead to serious bias in the...
Petter Næss, Morten Skou Nicolaisen, Arvid Strand -
Long term projections of cargo throughput are indispensable for port development plans. Although commodity flow projections are useful for governments, port authorities, terminal operating companies and port users, scientific research on commodity flow projections for ports is limited. Existing studies generally use econometric models that assume stable relationships between growth of port throughput and such variables as GDP growth and trade growth. This paper presents a method that was developed as part of the Port Vision 2030 project of Port of Rotterdam Authority. The method combines a model with expert judgement and commodity specific research. This combination enables incorporating disruptions of past growth patterns. The contribution of this paper is the description of this method, its application to the volumes in 2030 of all major commodities handled in the Hamburg – Le Havre range, with four different scenarios, while most studies deal with a few commodities in one port, and often for a shorter period and with less scenarios. The results show that in all scenarios, total throughput is expected to rise, although in three scenarios not as fast as in the previous two decades. Furthermore, intermediates and container flows are expected to continue to grow, while throughput of raw materials (iron ore, crude oil) may decline.
Long term projections of cargo throughput are indispensable for port development plans. Although commodity flow projections are useful for governments, port authorities, terminal operating companies and port users, scientific research on commodity flow projections for ports is limited. Existing studies generally use econometric models that assume stable relationships between growth of port throughput and such variables as GDP growth and trade growth. This paper presents a method that was developed as part of the Port Vision 2030 project of Port of Rotterdam Authority. The method combines a model with expert judgement and commodity specific research. This combination enables incorporating disruptions of past growth patterns. The contribution of this paper is the description of this method, its application to the volumes in 2030 of all major commodities handled in the Hamburg – Le Havre range, with four different scenarios, while most studies deal with a few commodities in one...
Long term projections of cargo throughput are indispensable for port development plans. Although commodity flow projections are useful for governments, port authorities, terminal operating companies and port users, scientific research on commodity flow projections for ports is limited....
Peter W. de Langen, Jaco van Meijeren, Lóránt A. Tavasszy -
Based on specific characteristics of mobility, the cross-border commuter status still has some ambiguities, whether in legal, geographic, economic or more generally in social or cultural terms. This paper aims at providing theoretical advancement to this specific cross-border mobility, especially through the transfer of a theoretical model using a cross-scale analysis based on two complementary concepts. The first corresponds to ‘border confirming’ and is measured at the macro level, including the economic differentials on both sides of the border. The second concept is called ‘border transcending’ and focuses on the individual level. It is based on the assessment of the psychosocial barriers that may fade as the daily practices of the border rise. This exploratory approach is tested within the European context of Benelux. The results, although they cannot be generalised due to a lack of comparable data, offer research perspectives. So far, the existence of a cross-border catchment area, tested on the Belgian cross-border commuters working in Luxembourg, is a reality for many.
Based on specific characteristics of mobility, the cross-border commuter status still has some ambiguities, whether in legal, geographic, economic or more generally in social or cultural terms. This paper aims at providing theoretical advancement to this specific cross-border mobility, especially through the transfer of a theoretical model using a cross-scale analysis based on two complementary concepts. The first corresponds to ‘border confirming’ and is measured at the macro level, including the economic differentials on both sides of the border. The second concept is called ‘border transcending’ and focuses on the individual level. It is based on the assessment of the psychosocial barriers that may fade as the daily practices of the border rise. This exploratory approach is tested within the European context of Benelux. The results, although they cannot be generalised due to a lack of comparable data, offer research perspectives. So far, the existence of a cross-border...
Based on specific characteristics of mobility, the cross-border commuter status still has some ambiguities, whether in legal, geographic, economic or more generally in social or cultural terms. This paper aims at providing theoretical advancement to this specific cross-border mobility,...
Philippe Gerber