Tom 19 (2018): Zeszyt 1 (March 2018)

The work is devoted to the study of the possibilities to apply the System Dynamics method for the analysis of processes at the road transport enterprises. The study contains a concise review on examples of three simulation paradigms application for creating models, associated with the road motor transport. The following paradigms were under consideration: Discrete Event, Agent Based, and System Dynamics. Furthermore, the paper describes the causal loop diagram designed using the principles of system dynamics. This diagram is a qualitative model that represents the relationships between the main factors affecting the performance indicators of a road transport enterprise. The quantitative model constructed using the principles of system dynamics is also represented. The mentioned model reflects the process of functioning of a road transport enterprise during the year. The model is developed using Vensim simulation software.

For a safe overtaking manoeuvre on two-lane highways, drivers need a sufficient sight distance along the roadway, but it depends on the traffic environment. To provide an adequate Passing Sight Distance (PSD), a number of models have been proposed since the initial model introduced by American Association of State Highways and Transport Officials (AASHTO) in 1954. It is a current design practice in Sri Lanka as well, however, not validated for local traffic conditions. This paper will present an alternative PSD model and an evaluation of AASHTO model for national highway design. Experiment was based on GPS data collection. In conclusion, PSD demand was satisfied by AASHTO PSD under mix traffic conditions, but not the safety concerns for speeds greater than 80 km/h, while alternative model successful for all speeds.

The influence of the side friction activities on the speed has been analyzed in the present study by conducting series of traffic field surveys. Pedestrian movements, parked vehicles and entry-exit of vehicles from surroundings, and wrong way movements are observed from videos and analyzed to estimate weighing factors. To examine the combined effects of all the activities the weighing factors are used to determine total value of side friction on the road. The study suggests model to estimate average speed of vehicular stream with the effect of side friction and volume on the roads section. It was found that the vehicular speed decreases as side friction increases at all the levels of traffic volume. However, no change in the speed was observed at lower level side friction. Capacity value obtained for combined data based on Greenshield’s theory that showed 9% reduction in the value considering with and without side friction.

To reduce the Sulphur emission from shipping and ensure clean shipping, a number of Sulphur Emission Control Areas (SECA) were enforced in special areas around the globe. From 2015, in SECA, ship owners are not allowed to use fuel with more than 0.1% Sulphur content. One of the major concerns for the SECA regulation is that maritime stakeholders have had to take into consideration the costs as well as the tolerable risks of their compliance investment options. Besides that, low freight rates have increased the competition and had caused financial pressure on ship owners so that lower capital reserves and low credibility levels limit the manoeuvring space for investment activities.

The indications from BSR after 2015 showed that the low fuel price has eased the economic effects of the SECA regulation and as a result, most ship owners have delayed their investment decisions. Even though the postponement of emission abatement techniques seems to have reduced the compliance expenses for SECA, they, however, did not improve the position of shipowners relative to their competitors. Consequently, new policy instruments to stimulate innovation, to raise competitiveness and to comply with the new environmental regulations are needed. It would have been easier to hedge fuel price volatility and offer maritime logistics services for a lower price, but to be able to ensure sustainable results in long-term, maritime stakeholders must be ready to device astute strategies that can propel them to unparalleled advantage.

This research first appraised the investment risks and payback period associated with the scrubber using different capital budgeting methods. It further illustrated the Maritime Energy Contracting (MEC) model as a market mechanism for the delivery of a cost-effective emission reduction using the scrubber technology as well as an instrument to realise a competitive advantage for ship operators. The results are empirically validated by case studies from BSR.

Dynamically changing economic conditions influence the growing demand of various freights transportation. Inevitably, the demand for heavy and oversized freight transportation is increasing, which is quite problematic. In many cases, it is very difficult to standardize the technology of heavy and oversized freight transportation. Decisions are necessary, which would allow to deliver heavy or oversized freight to the destination place, allocating fewer funds as possible for infrastructure improvements, choosing the most appropriate mode of transport for such freight transportation or using advantages of multimodal (combined) transport. In this article there will be selected methodology of heavy and oversized freight transportation system, carrying heavy and oversized freight by road transport. There will also be made an approval of this methodology, based on a hypothetical route within Lithuanian territory.

Safety of aircrafts exploitation is estimated by means of the using the results of the prognoses of the dangerous factors which could be take place during the flight in the off-design conditions. The risk - approach, based on the fuzzy sets methods, is discussed and find out the paths leading to the catastrophes of the different types of the vessels. The dangerous (Unsafeness, Hazard) is the discrete state with the factors which could be take place during the flight in the off-design conditions. It was suggested to find out the paths leading to the catastrophes under condition of the rare events with probabilities “almost zero”.