Volumen 14 (2013): Heft 4 (December 2013)

The paper describes the analysis and discussion of the network systems in case of the critical situation that happens during ordinary work. The formal model is proposed - based on the two types of real sophisticated network systems - with the approach to its modelling based on the system behaviour observation. The definition of the critical situation sets are created by reliability, functional and human reasons. No restriction on the system structure and on a kind of distribution describing the system functional and reliability parameters is the main advantage of the approach. The proposed solution seems to be essential for the owner and administrator of the transportation systems.

The paper discusses the discrete transportation system’s (DTS) availability problem in case of the critical situation, which happens during its ordinary work. The formal model of the transportation system suitable for modelling based on the system behaviour observation is proposed. Monte Carlo approach is in use for a simulation. The system’s availability is calculated as global metric to find if the system is able to realise the loaded set of tasks. The critical situation discussed there is caused by reliability, as well as by functional and human reasons. No restriction on the system’s topology and on a kind of distribution describing the system’s functional and reliability parameters is the main advantage of the approach. The proposed solution seems to be essential for the owner and administrator of the transportation systems.

Critical state of operation is reached by a system when it is exposed to an unexpected coincidence of faults (such as periodic rapid increase of the service demand, unavailability of a significant proportion of vehicle operators, simultaneous breakdown of all or a large part of the vehicle fleet). This leads to complete disruption of the transportation system, which persists even after the faults are removed. The duration of critical state of operation is defined as the time needed to resume normal operation after such an incident. It is shown that this time can be predicted using the simulation tools. Furthermore, a contingency plan is proposed, based on relocation of some resources between independent parts of a hierarchically organized transportation system. This contingency plan is analysed to determine the optimal percentage of resources to be relocated and the duration of this relocation.

In the context of a harmonized transnational transport system the green corridor concept represents a cornerstone in the development and implementation of integrated and sustainable transport solutions. Important properties of green corridors are their transnational character and their high involvement of public and private stakeholders, including political level, requiring new governance models for the management of green corridors.

Stakeholder governance models and instruments for green corridor governance are going to be developed and tested in different regional development projects in order to safeguard a better alignment of transport policies at various administrative levels and a strengthening of the business perspective. A crucial role in this context belongs to involvement of public and private stakeholders in order to safeguard efficient corridor performance.

The paper presents recent research results about green supply chain management in the frame of network and stakeholder model theory and its application to the stakeholders of green transport corridors.

Traffic safety applications using vehicle-to-vehicle (V2V) communication is an emerging technology and promising area within the ITS environment. Many of these applications require real-time communication with high reliability; to meet a real-time deadline, timely and predictable access to the channel. The medium access method used in 802.11p, CSMA with collision avoidance, does not guarantee channel access before a finite deadline. The well-known property of CSMA is undesirable for critical communications scenarios. The simulation results reveal that a specific vehicle is forced to drop over 80% of its packets because no channel access was possible before the next message was generated. To overcome this problem, we propose to use STDMA for realtime data traffic between vehicles. The real-time properties of STDMA are investigated by means of the highway road simulation scenario, with promising results.

The basic aim of managers in transport is to preserve and expand their share of the transport market. This should be done through prioritising quality and customer service, preservation and expansion field of transport enterprise activity to transport market on the basic of priority orientation to quality and customer, maintaining transport networks and applying the latest knowledge from research. It should also involve making a contribution to favourable indicators of economic activity, and a consideration of environmental change. This paper deals with customer requirements, the possibility of quantifying customer requirements and the recognition of future trends on the basis of assessments of recent quantitative results and the application of managers’ knowledge and techniques.

The development of the Public Transport (PT) services in the last decade is characterized by wide implementation of various information systems and technologies, which cover different transport services, such as traffic planning, traffic network monitoring, management of operation of PT fleets, providing information to the passengers, ticketing payment, etc. The article considers the research part of a large EU-funded project POLITE aimed at public transport sector and increasing the awareness of infomobility services and PT attractiveness through the application of identified Good Practices and Best Practices. The objective of this paper is presentation of the methodology of benchmarking and assessment of Good Practices and choice of the best one on the basis of the multi-criteria comparative analysis. For assessment of Good Practices the AHP (Analytic Hierarchy Process) method is applied.