The European postal directives and Serbian legislation as well define the quality standards for universal service obligations at the aggregate level, i.e. for all postal items transferred by the postal operator. This paper proposes a new concept where the transit time is defined by the customer and specified for each shipment. The paper considers three different models of this new concept. However, the one where a customer could choose between two alternatives: D+1 and D+3 transfer, is analysed in details. By using the attitudes of examined customers, forecasting methods and analysis of revenues from the past, it is assessed at what price the new postal service should be offered to achieve the highest revenue. The proposed methodology was tested and verified in the case of the Post of Serbia. The results indicate that the best would be to offer the service D+1 at the 40% increased price compared to the existing prices.
The traffic behaviours of commuters may cause traffic congestion during peak hours. Advanced Traffic Information System can provide dynamic information to travellers. Due to the lack of timeliness and comprehensiveness, the provided information cannot satisfy the travellers’ needs. Since the assumptions of traditional route choice model based on Expected Utility Theory conflict with the actual situation, a route choice model based on Game Theory is proposed to provide reliable route choice to commuters in actual situation in this paper. The proposed model treats the alternative routes as game players and utilizes the precision of predicted information and familiarity of traffic condition to build a game. The optimal route can be generated considering Nash Equilibrium by solving the route choice game. Simulations and experimental analysis show that the proposed model can describe the commuters’ routine route choice decision
exactly and the provided route is reliable.
Existing classification of the Croatian seaports does not fit the level and meet the needs of the economic development of the Republic of Croatia, particularly after the Republic of Croatia joined the European Union. Equalizing public service offered by a port with the purpose of the port itself (general purpose – port open for public traffic, special purpose – port not open for public traffic) limits the economic development and aggravates the implementation of the basic market policies of the EU. Therefore, modernisation of the basic classification of ports in the Croatian legislation is suggested. Basic categorization of ports should be as follows: public service ports, private service ports and private ports for private needs of an entrepreneur.
Participating in the automotive industry brings new responsibilities for suppliers who, in order to meet customer demands, must strive towards improving business processes, while at the same time reducing costs. These demands can disrupt the operations of companies that do not have a system for controlling logistics costs. On the other hand, customer demands can be the cause of other types of disruptions in companies that have such a system in place, stemming from an excessive focus on cost reduction. To tackle this problem, a survey was conducted on a sample of 30 Slovenian companies that operate as suppliers in the automotive industry. Its objective was to determine how different customer demands along the supply chain can affect the business processes of suppliers and the level of logistics costs. The survey revealed that companies that use a system for controlling logistics costs experience fewer disruptions in their business processes in their efforts to satisfy customer demands. These companies also display a higher level of integration of business processes and use a different approach when dealing with the various participants of the supply chain. The survey also sets clear participation guidelines for suppliers in the supply chain of the automotive industry and points out how companies can benefit from using a system for controlling logistics costs in other ways, aside from the cost controlling aspect.
Freeway greening and traffic safety has aroused more and more attention. The purpose of this study is to investigate the role of flexible green planting in buffering out-of-control vehicles. The stopping distances of vehicle rushing into greening were tested at 8 group of initial speeds range from 5km/h to 40km/h in green belt, and a simplified mathematical model was built up to simulate the buffering process. The results indicated that the greening plants have certain buffering effect on vehicles and alleviate the crash damage within 30m of stopping distance for the vehicles under 40km/h, while the simplified mathematical model could reflect the buffering process of the plants actually by simulating the speed attenuation process, and it was found that the two types of resistance produced by the plants, i.e. counterforce of plants trunks and friction of branches and leaves, are the major factors during the vehicle deceleration.
Increasing traffic demand has already reached the capacity of existing traffic facilities in most cities. In order to alleviate the traffic pressure and expand the capacity of the road network, constructing flyovers has become an effective way in most cities in China. During the period of the flyover construction, work zones occupy road space, impact traffic flow characteristics and driver behaviour; therefore, this causes a significant reduction of the capacity. Researching of the traffic flow characteristics during the period of flyover construction can improve traffic organization and traffic safety around work zones. This study analyses the traffic flow characteristics around the flyover work zone based on the site data collected in Hohhot City, China. This study shows that the traditional Logistic model for the equilibrium speed-density relationship is not applied to the traffic flow around the flyover work zone. Based on an in-depth analysis of the traffic flow characteristics and specific driver behaviours, this paper proposes an improved Logistic model to depict the equilibrium speed-density relationship around the flyover work zone. To analyse the mathematical characteristics of the speed-density relationship, this paper proposes a method to insert virtual data points into the initial data, which can make the fit curve be continuous.
Accelerating Discoveries in Traffic Science |
2024 © Promet - Traffic&Transportation journal