Organisation of LTL networks - consequences for intermodal transport

In the transportation sector the issue of intermodal transport has grown significantly more important over the years and is a potential means toward sustainable transportation systems. One important type of user of intermodal transport is less-than-truck load (LTL) service providers. LTL networks often consist of a forwarder and a number of hauliers in a more or less formal organisation. They often work together for many years with the shared strategic purpose to produce transport services, an organisation form that in the construction industry is called a quasifirm. In the relationship between haulier and forwarder the direct mode choice is often made by one of them while they represent different levels of decision-making and hold different responsibilities. Consequently, the forwarder-haulier organisation--the quasifirm--can be expected to influence the use of intermodal road-rail transport. The purpose of this paper is to describe the business setup between haulier and forwarder as a quasifirm and by means of this concept to outline possible influences on issues important for intermodal road-rail transport. The theory of the quasifirm is presented. To empirically show the existence of the quasifirm in LTL networks, a case study of the forwarder Schenker with their associated hauliers is matched to the theory. The paper establishes the studied forwarder with its associated hauliers as a quasifirm, an organisation form that is proved to have some beneficial characteristics. However, this organisation form also has some less beneficial consequences for the use of intermodal transport

Time perspectives on intermodal transport of consolidated cargo

Intermodal road-rail freight transport is often argued to have certain cost and time handicaps against all-road transport. Based on theory defining the elements transport time, order time, timing, punctuality and frequency, literature on modal choice is surveyed. With few exceptions, transport time and punctuality is top ranked, while frequency and timing is regarded as less important by respondents. Timing is excluded in some studies and order time is not found. The time elements are also used for comparing the characteristics of intermodal transport and all-road transport. Particular attention is paid to the preconditions for using intermodal transport as part of consolidation networks with subsequent terminal handlings. Since time aspects in transportation are highly contextual, the analysis is deepened within the framework of a case study focusing Schenker’s domestic transport services in Sweden. Schenker’s time requirements are matched against the times CargoNet, their main supplier of intermodal terminal-to-terminal services, can offer. It is concluded that correspondence of the transport time between the consolidation network and the intermodal network are in fact not a strong prerequisite to use intermodal transport, although correspondence of departure and arrival times is significantly higher for the intermodal relations regularly used by the logistics service provider. Regarding timing, adjusting departure and arrival times by one hour will not increase the competitiveness for the consolidated cargo significantly, more profound adjustments are required. The order time of the intermodal freight transport service is not well suited to consolidated cargo due to volume information unavailability. The consolidated cargo schedule is sensitive for rather small deviations in punctuality

Gaseous mercury flux from salt marshes is mediated by solar radiation and temperature

Salt marshes are ecologically sensitive ecosystems where mercury (Hg) methylation and biomagnification can occur. Understanding the mechanisms controlling gaseous Hg flux from salt marshes is important to predict the retention of Hg in coastal wetlands and project the impact of environmental change on the global Hg cycle. We monitored Hg flux from a remote salt marsh over 9 days which included three cloudless days and a 4 mm rainfall event. We observed a cyclical diel relationship between Hg flux and solar radiation. When measurements at the same irradiance intensity are considered, Hg flux was greater in the evening when the sediment was warm than in the morning when the sediment was cool. This is evidence to suggest that both solar radiation and sediment temperature directly influence the rate of Hg(II) photoreduction in salt marshes. Hg flux could be predicted from solar radiation and sediment temperature in sub-datasets collected during cloudless days (R2 = 0.99), and before (R2 = 0.97) and after (R2 = 0.95) the rainfall event, but the combined dataset could not account for the lower Hg flux observed after the rainfall event that is in contrast to greater Hg flux from soils after rainfall events

Factors Driving Mercury Variability in the Arctic Atmosphere and Ocean over the Past 30 Years

[1] Long-term observations at Arctic sites (Alert and Zeppelin) show large interannual variability (IAV) in atmospheric mercury (Hg), implying a strong sensitivity of Hg to environmental factors and potentially to climate change. We use the GEOS-Chem global biogeochemical Hg model to interpret these observations and identify the principal drivers of spring and summer IAV in the Arctic atmosphere and surface ocean from 1979–2008. The model has moderate skill in simulating the observed atmospheric IAV at the two sites (r ~ 0.4) and successfully reproduces a long-term shift at Alert in the timing of the spring minimum from May to April (r = 0.7). Principal component analysis indicates that much of the IAV in the model can be explained by a single climate mode with high temperatures, low sea ice fraction, low cloudiness, and shallow boundary layer. This mode drives decreased bromine-driven deposition in spring and increased ocean evasion in summer. In the Arctic surface ocean, we find that the IAV for modeled total Hg is dominated by the meltwater flux of Hg previously deposited to sea ice, which is largest in years with high solar radiation (clear skies) and cold spring air temperature. Climate change in the Arctic is projected to result in increased cloudiness and strong warming in spring, which may thus lead to decreased Hg inputs to the Arctic Ocean. The effect of climate change on Hg discharges from Arctic rivers remains a major source of uncertainty.Earth and Planetary SciencesEngineering and Applied Science

Organisation of LTL networks - consequences for intermodal transport

In the transportation sector the issue of intermodal transport has grown significantly more important over the years and is a potential means toward sustainable transportation systems. One important type of user of intermodal transport is less-than-truck load (LTL) service providers. LTL networks often consist of a forwarder and a number of hauliers in a more or less formal organisation. They often work together for many years with the shared strategic purpose to produce transport services, an organisation form that in the construction industry is called a quasifirm. In the relationship between haulier and forwarder the direct mode choice is often made by one of them while they represent different levels of decision-making and hold different responsibilities. Consequently, the forwarder-haulier organisation--the quasifirm--can be expected to influence the use of intermodal road-rail transport. The purpose of this paper is to describe the business setup between haulier and forwarder as a quasifirm and by means of this concept to outline possible influences on issues important for intermodal road-rail transport. The theory of the quasifirm is presented. To empirically show the existence of the quasifirm in LTL networks, a case study of the forwarder Schenker with their associated hauliers is matched to the theory. The paper establishes the studied forwarder with its associated hauliers as a quasifirm, an organisation form that is proved to have some beneficial characteristics. However, this organisation form also has some less beneficial consequences for the use of intermodal transport

Intermodal Transport in Less-than-Truckload Networks

In producing transport services several different transport modes are available. Through the last decades, road transport has increased rapidly. This development is recognised as unsustainable. A more sustainable alternative is intermodal transport. Less-than-truckload (LTL) networks, i.e. networks designed to transport consignments not filling a truck, are historically based on road transport. Intermodal transport is an alternative on some routes in the LTL networks. A transport mode choice is at hand on these routes.The purpose of this thesis is to contribute to the understanding of how the mode choice between intermodal transport and road transport is made in LTL networks. Previous studies of the mode choice have identified factors that are important but also emphasise the complex nature of the mode choice. However, including the context in which the mode choice is made can provide a better understanding of the mode choice complexity.Time pressure is high in LTL networks. Five aspects of time that are important in the mode choice in the studied LTL network are identified. These can be used to broadly measure the compliance of IRRT to consolidated cargo, a LTL service. Addressing the complexity of the mode choice, the decision-making that includes the mode choice is structured by applying theoretical perspectives of decision-making and company operations. A general and descriptive model is the result. This structure is a tool to explain how the decision-making that includes the mode choice is constituted.In LTL networks forwarders often contract hauliers to perform the transport services. This entails the mode choice being distributed to the hauliers. Forwarders, the controlling actors of LTL networks, thus have limited influence over the mode choice. Applying the quasifirm organisational perspective to the organisation of LTL networks provides some explanatory concepts showing the strengths and weaknesses of this organisation structure when it concerns the mode choice. Consequently, the thesis shows some different aspects of the mode choice in LTL networks by both empirical investigation and theoretical application

Long-distance hauliers\u27 transport mode choices

Intermodal transport has benefits over all-road transport in lower external and internal cost with a resulting large potential but many consider the development of intermodal transport not to be satisfactory. This situation is attributed to that barriers and constraints to intermodal transport exist. In previous research, several levels of decision making have been argued to influence the demand for road transport. But the actual choice between all-road and intermodal transport is often taken by a mode decision making firm. Hauliers are one category of users of intermodal transport, thus a mode decision making firm. Because of the hauliers anticipated central role in the mode choice the purpose of the paper is to analyze how a hauliers decision making affects the choice between all-road and intermodal transport. The mode choice is described and analysed as part of strategic, tactical and operational decision making with an input-transformation-output perspective of the haulier. This perspective tries to illustrate the complexity of the mode choice that is often stressed in mode choice literature but more seldom explained. With this model of the context of the mode choice the paper explores how the mode choice is treated at two hauliers. The basis for the mode choice at the hauliers is largely determined at the strategic level in the decision of what resources to acquire. Time flexible resources are preferred which results in that all-road transport is the chosen alternative over intermodal transport. The paper shows that some resources can be rescheduled for intermodal transport at the tactical level. Rescheduling of resources is not done regularly or in a systematic way. At the operational level all-road resources are filled first which have the effect that intermodal resources are used according to the daily capacity requirements

Intermodal Transport in Less-than-Truckload Networks

In producing transport services several different transport modes are available. Through the last decades, road transport has increased rapidly. This development is recognised as unsustainable. A more sustainable alternative is intermodal transport. Less-than-truckload (LTL) networks, i.e. networks designed to transport consignments not filling a truck, are historically based on road transport. Intermodal transport is an alternative on some routes in the LTL networks. A transport mode choice is at hand on these routes.The purpose of this thesis is to contribute to the understanding of how the mode choice between intermodal transport and road transport is made in LTL networks. Previous studies of the mode choice have identified factors that are important but also emphasise the complex nature of the mode choice. However, including the context in which the mode choice is made can provide a better understanding of the mode choice complexity.Time pressure is high in LTL networks. Five aspects of time that are important in the mode choice in the studied LTL network are identified. These can be used to broadly measure the compliance of IRRT to consolidated cargo, a LTL service. Addressing the complexity of the mode choice, the decision-making that includes the mode choice is structured by applying theoretical perspectives of decision-making and company operations. A general and descriptive model is the result. This structure is a tool to explain how the decision-making that includes the mode choice is constituted.In LTL networks forwarders often contract hauliers to perform the transport services. This entails the mode choice being distributed to the hauliers. Forwarders, the controlling actors of LTL networks, thus have limited influence over the mode choice. Applying the quasifirm organisational perspective to the organisation of LTL networks provides some explanatory concepts showing the strengths and weaknesses of this organisation structure when it concerns the mode choice. Consequently, the thesis shows some different aspects of the mode choice in LTL networks by both empirical investigation and theoretical application

Time perspectives on intermodal transport of consolidated cargo

Intermodal road-rail freight transport is often argued to have certain cost and time handi-caps against all-road transport. Based on theory defining the elements transport time, order time, timing, punctuality and frequency, literature on modal choice is surveyed. With few exceptions, transport time and punctuality is top ranked, while frequency and timing is re-garded as less important by respondents. Timing is excluded in some studies and order time is not found. The time elements are also used for comparing the characteristics of intermodal transport and all-road transport. Particular attention is paid to the preconditions for using intermodal transport as part of consolidation networks with subsequent terminal handlings. Since time aspects in transportation are highly contextual, the analysis is deepened within the framework of a case study focusing Schenker’s domestic transport services in Sweden. Schenker’s time requirements are matched against the times CargoNet, their main supplier of intermodal terminal-to-terminal services, can offer. It is concluded that correspondence of the transport time between the consolidation network and the intermodal network are in fact not a strong prerequisite to use intermodal transport, although correspondence of departure and arrival times is significantly higher for the inter-modal relations regularly used by the logistics service provider. Regarding timing, adjusting departure and arrival times by one hour will not increase the competitiveness for the consoli-dated cargo significantly, more profound adjustments are required. The order time of the in-termodal freight transport service is not well suited to consolidated cargo due to volume in-formation unavailability. The consolidated cargo schedule is sensitive for rather small devia-tions in punctuality