Longer Routes Research Articles

Revealing the freight market risk in Istfix shipping area

This study analyses the market risk of the freight rates of Istfix shipping area, where small coaster size of dry/general cargo mini bulkers ranging from 2,000 dwt to 12,000 dwt operate on Black Sea-Mediterranean-Continent routes. Having used VaR and expected shortfall as the market risk measures, we have found that the market risk is higher on longer routes in this region. However, the results do not suggest a significant relationship between the market risk of freight rates and that of coaster tonnages. Overall, the market risk in Istfix shipping area has been found to be much lower than in the international Baltic handysize index (BHSI), a proxy international index of relatively small sized vessels. The findings provide a better understanding of Istfix shipping area compared to BHSI for tramp market participants and speculators in freight derivatives markets for hedging and speculative purposes in their investment strategies and financial decision making processes.

Paving the Road to Export: Assessing the Trade Impact of Road Quality

Assessing the trade impacts of domestic transport costs is data demanding and analyses that examine the effects of road quality, a critical aspect in regional and public policy, practically do not exist in the international trade literature. The few studies available rely mostly on distance-based measures as proxies of transport costs which impede analyzing the trade effects of transport-infrastructure improvements. In this paper, we combine highly disaggregated records of export flows with detailed geo-referenced information of the Colombian transport network, including its road quality, as well as real measures of transport costs of shipping goods within the country to measure the trade impacts of improving road quality. We find that the trade effects of improvements in road quality are relatively small on average; however, there is considerable heterogeneity in the magnitude of the effects. We show that longer routes have larger shares of their roads in poor conditions; accordingly, the trade impacts of shipments originated in remote regions are found to be quite substantial.

Link-Node Characterization for Energy-Efficient Communication in a Static Random Wireless Sensor Network

Studies of wireless networks often work with a relatively high communication range so that each node typically communicates with a high number of neighbors. This is necessary, with a random placement, to avoid loss of coverage or connectivity. However, communicating through remote neighbors requires more energy, which can be a severe disadvantage since energy is often critical in this type of network. By comparing two-ranges, one to ensure coverage and one to save energy, we identify link-nodes which play an essential role to keep the network connected. Characterizing these nodes and their occurrence in communication routes will help to save energy and increase lifetime of the overall network. Without precautions, these link-nodes receive a high traffic load. Using simulations we find that slightly longer routes can avoid link-nodes and thus reduce average energy consumption. Network lifetime can be extended by identifying these nodes at startup and reducing their energy consumption wherever possible.

The effect of signalised intersections on dynamic traffic assignment solution stability

This article examines a continuous-flow analytic dynamic traffic assignment (DTA) model with consideration of isolated uncoordinated traffic signals. The dynamic network loading component of the DTA model relies on trajectories and anticipated arrival order to nodes in order to achieve consistency between flow propagation along routes and kinematic waves (physical queue) representation of single link traffic behaviour. We compare results between a model where queues with random arrivals and deterministic departure rates are captured by non-stationary cycle-to-cycle Markov chains, and a model where only exit capacity effects of traffic signals are considered. Numerical examples illustrate that overall the model with Markov chains behaves properly, and captures interesting impacts of random queuing traffic signal delays on route choice and network level DTA solutions. A particular focus of this article is the issue of solution stability and its relationship to model specification and discretisation. We discuss the connection between DTA models and general finite element models in this respect, particularly regarding lag options in the discrete form of the equilibrium condition. Our results regarding these options, known as ‘forward’ versus ‘backward’ Euler method, or as ‘reactive’ versus ‘predictive’ user-equilibrium, confirm previous findings. In addition, the results show that the model specification with Markov chain representation of traffic signals enhances solution instability, and exhibits spurious oscillations even if backward Euler method is used. The results suggest that longer route choice intervals reduce oscillations, contrary to the typical behaviour in finite element models where stability generally improves when the resolution is refined.

To jump or not to jump? Strategies employed by leisure and sport horses

Show jumping is one of the most popular equestrian disciplines although strategic jumping per se is seldom used by free-living horses when negotiating obstacles that they might otherwise avoid. To establish if horses are naturally motivated to jump, we examined horses in a free-choice situation when negotiating various obstacles under test conditions. Eighteen leisure horses (LHs) and 16 sport horses (SHs) participated in a number of 2-choice tests. First, horses were presented with 2 optional routes during a “free-choice test” to reach a food stimulus. The choices were a shorter route (over an obstacle) or a longer route (around the obstacle). During 8 consecutive trials, the horses encountered an increase in obstacle height on every second trial as follows: 0, 20, 35, and 50 cm. In the “ridden test” after an initial conditioning period, the horses were tested with a Y-maze formation during 3 consecutive trials, where one element of the maze contained an obstacle arm (OA). The horses walked or trotted over the obstacle most frequently (59.9%) and jumped the obstacle in only 10.7% of the cases. For both the LH and SH groups, the horses' motivation to traverse the obstacle decreased as the obstacle height increased and only 44.1% of horses actually negotiated the 50-cm obstacle as compared with the 20-cm obstacle (85.3%). The LH group preferred to go around the obstacle significantly more often than the SH group (24 trials, 16.7% vs. 9 trials, 7.0%, for SH and LH, respectively; χ 2 = 6.81, N = 33, P = 0.0090). The LH group used a jumping strategy to clear the obstacle far less frequently (6 trials, 4.2%) than the SH group (23 trials, 18.0%; χ 2 = 9.96, N = 29, P = 0.0023). In the Y-maze trials, the LH group exhibited preference (40 per 54 trials, 74.1%; χ 2 = 12.5, P < 0.0001), and the SH group failed to exhibit any preference (20 per 48 trials; χ 2 = 1.33, P = 0.3123). There was no evidence of any correlation between the motivation to clear the obstacle and total number of OA choices in either the LH group ( r s = 0.13, P = 0.9594) or the SH group ( r s = −0.25, P = 0.3492). The findings from the present study indicate that SHs are motivated and willing to jump obstacles more often than are LHs under similar conditions. However, the apparent reluctance of the horses overall to continue jumping as the obstacle height increases suggests that, in general, many horses could easily encounter excessive demands (overfacing) in sport. This issue should be carefully monitored in terms of equine training, competition, and welfare.

Panama Canal expansion: emission changes from possible US west coast modal shift

Background: We analyzed the potential for the Panama Canal expansion to change CO2 and criteria pollutant emissions (oxides of nitrogen, oxides of sulfur and particulate matter) from Asia–US container flows by estimating the modal shift from landside truck/rail network to larger ships enabled by canal expansion. We develop an intermodal case study comparison within the Geospatial Intermodal Freight Transportation framework, assuming potential diversion of 1.2 million 20-foot equivalent units (TEUs) to 5000 origin–destination pairs. Results: Potential TEU diversions of land-bridge transport through an expanded canal reduced mode-specific emissions substantially, but land-bridge emission reductions due to cargo diversion to post-Panamax vessels, with lower emissions per TEU, cannot offset higher waterborne emissions from longer routes. Conclusion: Green-freight policy measures must consider multimodal network solutions to maximize emission benefits.

Investigation to the Driving Factors of the Increase in the Carbon Emission of Chinese Transportation Based on Principal Component Analysis and Logarithmic Mean Divisia Index Decomposition Method

This paper selects driving factors with high contribution rate for carbon emission using Principal Component Analysis and regroups these factors. Then, based on the Method of Logarithmic Mean Divisia Index (LMDI) Decomposition, it obtains and analyses the contribution rates of ten driving factors of the carbon emission of China’s transportation sector. Our study indicates that: (1) from 1996 to 2008, the number of cars per capita, GDP per capita, the volume of fright and the proportion of urban population are positive drivers of the increase in the carbon emission of China’s transportation sector, and the number of cars per capita is the key one; (2) the negative drivers are energy intensity and degree of traffic congestion, so public transport priority, population control and longer transportation routes can lessen the CO2 emission of transportation; (3) an adjusted fuel structure with higher diesel occupation, keeping the transportation industry consistent with the growth of national economy and more efficient freight transportation may decrease CO2 emission.

Study on Improved Tabu Search Algorithm for Min-Max Vehicle Routing Problem

The paper is focused on the Min-Max Vehicle Routing Problem. And solve this type of problems utilizing improved tabu search algorithm from the overall situation. According to the features of the problem, the essay centered the longest route to construct neighborhood structure. For the operation, 1-exchange and 2-opt* were applied, it can also fasten the speed of convergence, and boost the search efficiency. Finally, the good performance of this algorithm can be proved by experiment calculation and concrete examples.

Strategies of Young Pigeons during ‘Map’ Learning

The routes of young, inexperienced pigeons released at four sites up to 13·5 km from the loft were recorded with GPS-based tracking devices. The routes were found to differ from those of old, experienced pigeons in several aspects: (1) Although being oriented when departing, young birds show more scatter and larger deviations from the home direction, but usually restrict their flights to a semicircle. (2) They apparently ignore prominent landmarks near the loft that are clearly visible. (3) Their tracks are typically more complex, consisting of a number of distinctive phases where the young birds head in different directions, which results in significantly longer routes, often exceeding the direct home distances more than four times. (4) At the same time, young birds seldom venture further away from the release site than the direct distance to home. Their behaviour can be interpreted as exploration to obtain new information on the distribution of navigational factors to be included in their still rudimentary navigational ‘map’. At the same time, their flights seem to include elements of safety, like anchoring the flights around the release site and a sense of distance, which help to reduce the chance of getting lost.

Study on Tabu Search Algorithm for Min-Max Vehicle Routing Problem

The paper is focused on the Min-Max Vehicle Routing Problem (MMVRP). Tabu search algorithm is an algorithm based on neighborhood search. According to the features of the problem, the essay centered the longest route to construct neighborhood structure. For the operation, 1-move and 2-opt were applied, it can also fasten the speed of convergence, and boost the search efficiency. Finally, the good performance of this algorithm can be proved by experiment calculation and concrete examples.

On Improving Fairness and Providing Proportional Loss Differentiation in OBS Networks

Unfairness is a known undesirable characteristic of OBS networks whereby data flows which traverse longer routes and/or bottleneck links suffer higher data loss. The solutions to this problem presented in the literature, which are mostly based on giving preference to the data flows with longer routes, have not achieved fully satisfactory results. We face the unfairness problem from a different perspective, and propose the Reactive Unfairness Reduction technique, or RUR, which reactively gives transmission priority to those flows which are currently undergoing higher data loss rates. We also present Proportional differentiation RUR (P-RUR), which extends the operation of RUR for not only providing fairness, but also edge-to-edge proportional loss differentiation. Both mechanisms are evaluated through simulation.

Chemotaxis can take plant-parasitic nematodes to the source of a chemo-attractant via the shortest possible routes

It has long been recognized that chemotaxis is the primary means by which nematodes locate host plants. Nonetheless, chemotaxis has received scant attention. We show that chemotaxis is predicted to take nematodes to a source of a chemo-attractant via the shortest possible routes through the labyrinth of air-filled or water-filled channels within a soil through which the attractant diffuses. There are just two provisos: (i) all of the channels through which the attractant diffuses are accessible to the nematodes and (ii) nematodes can resolve all chemical gradients no matter how small. Previously, this remarkable consequence of chemotaxis had gone unnoticed. The predictions are supported by experimental studies of the movement patterns of the root-knot nematodes Meloidogyne incognita and Meloidogyne graminicola in modified Y-chamber olfactometers filled with Pluronic gel. By providing two routes to a source of the attractant, one long and one short, our experiments, the first to demonstrate the routes taken by nematodes to plant roots, serve to test our predictions. Our data show that nematodes take the most direct route to their preferred hosts (as predicted) but often take the longest route towards poor hosts. We hypothesize that a complex of repellent and attractant chemicals influences the interaction between nematodes and their hosts.

Paving the Road to Export: The Trade Impacts of Domestic Transport Costs and Road Quality

The literature examining the effects of domestic transport costs on trade flows is scarce. The few studies available rely mostly on distance-based measures as proxies of transport costs which impede analyzing the trade impacts of transport-infrastructure improvements, a critical aspect in regional and public policy. Applying a novel methodology that combines real freight costs and Geographic Information System (GIS) analysis to the case of Colombia, this paper measures the extent to which domestic transport costs -from the place of production to the port of shipment- act as a friction to international trade. Domestic transport costs are found to significantly affect the prospects of exporting. For instance, regions within the country with transport costs in the 25th percentile export around 2.3 times more than regions with transport costs in the 75th percentile, once other factors are controlled for. Export increases from road improvements are found to be larger in regions with initially higher transport costs. This is because regions with initially higher transport costs are normally associated with longer routes and those tend to have larger shares of roads in poor conditions

Pipeline Alignment Optimization: Automated GIS-Based Approach

The shortest route from home to work may not be the best alternative, and a longer route may be fastest or safest. Hence, the best route reflective of one factor may not be the ultimate best alternative. This paper discusses a geographic information system (GIS)–based application to analyze and rank a number of potential pipeline routes based on accumulated weights of individual segments composing the route. The goal of this application was to automate the process of defining more than one potential route. Designers and stakeholders determine project-specific criteria and assign weighting factors to each. Additionally, individual scores are assigned to each segment in the so-called decision matrix which is a project-specific spreadsheet. The weights and costs are extracted from the decision matrix and imported as attributes for each segment in the GIS pipe network layer based on the unique segment ID. A network analyst routine was programmatically used to identify a number of potential pipeline routes that were then stored in an output feature class and eventually exported to Microsoft Excel, where a summary chart was generated to summarize the findings. The application was used on a test case in the western United States. The application was developed using Visual Basic for Application and ArcObjects and was intended for use in ESRI’s ArcGIS Desktop 9.3.

Lowest Cost Intermodal Rail Freight Transport Bundling Networks: Conceptual Structuring and Identification

Bundling, the process of transporting goods belonging to different flows in a common vehicle (like train, barge or truck) or other unit during part of their journey, is a core business of the transport sector. Operators periodically evaluate their service networks and adjust their bundling operations. The adjustments respond to changing cost structures, changing competition and changing situations in terms of demand and performance requirements. One can distinguish direct bundling from different types of complex bundling, such as hub-and-spoke or line bundling. Complex bundling networks have intermediate exchange nodes and longer routes, but less vehicle routes. The latter means that required network volumes could be lower, service frequencies higher or vehicle loads larger. In this sense, complex bundling allows smaller flows to participate in the advantages of large-scale operations and therefore is an important option to successfully develop intermodal transport. The additional impedance of complex bundling networks has been and still is an incentive for intermodal rail freight operators to switch from complex to direct bundling. However, the flow sizes of many rail relations are too small for direct bundling. If nevertheless direct bundling is applied, trainloads or service frequencies decline and/or small flows will shift to the road sector. In this paper, which focuses on intermodal rail freight networks, we analyse the trends of bundling innovation, and discuss the operational mechanisms in bundling networks and their quantitative impact for the number of train routes, service frequency, the size of trainloads, and required network transport volume. Furthermore we identify which bundling types lead to large trainloads and lowest costs, given certain network transport volumes and certain service frequency requirements. On the basis of a large-scale comparison of bundling networks with large trainloads and ones with lowest costs we conclude, that a large trainload is a good first indicator for lowest cost network: if an intermodal basic bundling network has the largest technically allowed trainload and this is larger than of competing bundling types, the envisaged network is likely to also have the lowest network costs.

Exact algorithms for a selective Vehicle Routing Problem where the longest route is minimized

Abstract In this paper, we study a non-capacitated Vehicle Routing Problem (VRP) where not necessarily all clients need to be visited and the goal is to minimize the length of the longest vehicle route. An Integer Programming Formulation, a Branch-and-cut (BC) method and a Local Branching (LB) framework that uses BC as the inner solver are presented. Sharper upper bounds are obtained by LB, when the same time limit was imposed on the execution times of both approaches. Our results also suggest that the min-max nature of the objective function combined with the fact that not all vertices need to be visited make such problem very difficult to solve.

Scheduled service versus personal transportation: The role of distance

This paper presents a theoretical and empirical analysis of the relationship between frequency of scheduled transportation services and their substitutability with personal transportation (using distance as a proxy). We study the interaction between a monopoly firm providing a high-speed scheduled service and private transportation (i.e., car). Interestingly, the carrier chooses to increase the frequency of service on longer routes when competing with personal transportation because by providing higher frequency (at extra cost) it can also charge higher fares which can boost its profits. However, in line with the results of earlier studies, frequency decreases for longer flights when driving is not a viable option. An empirical application of our analysis to the European airline industry confirms the predictions of our theoretical model.

Scheduled Service Versus Personal Transportation: The Role of Distance

This paper presents a theoretical and empirical analysis of the relationship between frequency of scheduled transportation services and their substitutability with personal transportation, using distance as a proxy. We study the interaction between a monopoly fi rm providing a high-speed scheduled service and private transportation (i.e., car). Interestingly, the carrier chooses to increase the frequency of service on longer routes when competing with personal transportation because by providing higher frequency (at extra cost) it can also charge higher fares which can boost its profi ts. However, in line with the results of earlier studies, frequency decreases for longer flights when driving is not a viable option. An empirical application of our analysis to the European airline industry confi rms the predictions of our theoretical model.

EU Emissions Trading Scheme and Aviation: Quo Vadis?

The inclusion of aviation into the EU Emissions Trading Scheme (EU ETS) may have more surprises in store for small and medium-sized carriers than those airlines will appreciate. It is not the large international carriers with their climate change managers and environmental departments that have EU ETS on their agenda for years but, in particular, third country carriers or companies in business aviation that might get hit harder than others. Compliance with the new set of rules and procedures will be a challenge and the prework dimension should not be underestimated. Unfortunately, the time frame is tight and the policymakers and its administration do not seem to be too expeditious when it comes to enacting the necessary laws, regulations, and guidelines and providing the support the industry is requesting. On the other hand, the potential of the EU ETS concerning a distortion of competition, in particular, for European carriers, is not determined yet. It is feared that traffic from the United States to Asia will switch routes via the Gulf States, that is, not touching European airports and thus avoiding any extra costs. This would not only result in longer routes but also simultaneously have the counterproductive effect of creating more emissions. Therefore, although the concerted European action is a needful forerunner and acceptance in general is growing, a global approach is required more than ever and the industry’s hopes are high for the UN climate conference in Copenhagen in December this year.

Operational Development of Marine Highways to Serve the U.S. Pacific Coast

This paper examines the market volumes, service times, vessel characteristics, and economics for marine highways that would serve the U.S. Pacific Coast. This work was performed under contract to the Center for Commercial Deployment of Transportation Technologies. Market volumes were assessed by routes of interest and by filtering for cargo that would be eligible for marine highway service on the basis of the drayage distance and other factors. Sufficient daily truckload volumes exist in the Northern California to Southern California route to justify marine highways with multiple daily sailings of vessels with capacities of 450 to 700 trailers, should service times and economics prove to be competitive enough to divert cargo. Market volumes in the California to Pacific Northwest route are sufficient for daily sailings of smaller vessels with capacities of approximately 150 to 200 trailers. A door-to-door supply chain perspective was maintained, and discrete-event simulation was used to assess the service times and the vessel speeds required. The resulting voyage analysis served as input to both a parametric analysis of vessel characteristics and an economic analysis of marine highways by considering all maritime and land-side cost elements associated with the door-to-door movement of trailers. It was concluded that current truck rates are not high enough for marine highways to compete on the basis of cost in short next-day-turnaround markets, such as Northern California to Southern California. Marine highways are viable for longer routes such as those from California to the Pacific Northwest, where truck rates are higher and both distance and trucking hours-of-service regulations permit vessels to be time competitive at lower speeds.