Įvairūs grafo srautų minimizavimo arba maksimizavimo uždaviniai yra taikomi modeliuoti procesams logistikoje, kompiuteriniuose tinkluose, akcijų biržose, automobilių eisme ir t.t. Tokio uždavinio sprendimas esant dideliems grafams yra labai sudėtingas, todėl modelyje būna mažai kintančių parametrų arba modeliuojama tik dalis proceso. Tokio uždavinio pavyzdys (kuris ir bus nagrinėjamas) yra eismo modeliavimas keliuose. Kiekvienas vairuotojas bando pasiekti savo tikslą per minimalų galimą tuo metu esančiomis sąlygomis laiką. Tokiu būdu yra užimama „geriausia vieta“ kelyje, o kitiems vairuotojams užimtas kelias gali tapti neberacionalus ir bus pasirenkamas alternatyvus. Šioje vietoje atsispindi esminė tokio tipo uždavinio savybė: kiekvienas proceso dalyvis siekia maksimalios naudos sau, tokiu būdu tą naudą atimdamas iš kitų dalyvių. Šiu atveju „nauda“ yra vieta eisme. Darbe yra aprašytas eismo imitavimo sistemos modelis ir realizuotas tokia architektūra, kuri tinkama lygiagretiems skaičiavimams. Pateikta statistiniai gauto modelio analizavimo pavyzdžiai. Taip pat pasiūlyti keli algoritmai specifiniams uždaviniams spręsti, kaip dalinis modelio perskaičiavimas. / In this work we will try to apply various path search algorithm optimizations for solving traffic simulation problem. These optimizations are made on the basis of processes and patterns specific to car traffic. Other areas like logistics, money traffic and stocks should have their own specific optimizations. Primary selection criteria will be calculation time. Errors are also introduced by these optimizations, but benefits of solving more complex problems in much shorter time will outweigh those errors. Most of described algorithms are just modifications of traditional Dijkstra's algorithm. This allows to show step by step every optimization introduced, which we can split into 3 categories: Algorithms for finding shortest path in untouched graph, Algorithms for finding shorted path which need modified graph, Algorithms specific for traffic simulation. Algorithms up to graph transformations have been analyzed in previous works. These optimizations proved to be very perspective in point-to-point path search. Thou applying them to traffic modeling and introducing modeling specific optimizations is a relatively new research area. Also an algorithm imitating traffic laws has to be implemented. One of suggested optimizations could be called “fast partial recalculation”. This would allow a faster recalculation of main path loads. Assuming that traffic is the same and graph is slightly modified. A modified idea could be adapted for a recalculation with modified traffic loads. Vastly... [to full text]

Everyone has had the experience of sitting in a traffic jam, or of seeing cars bunch up on a road for no apparent good reason. Nowadays the quantity of vehicles in the Lithuanian cities are growing very fast. The necessity of circumstantial territory analysis emerged for increasing Transportation Systems Control demand. Microscopic traffic flow models are important for analyzing individual crossroads and assessing interaction between some vehicles. In this paper there are analyzed microscopic traffic flow model. In this paper there answered what effect is produced by small differences in the velocities of the cars. And we have that microscopic traffic flow is in stability when kT < 0.5 and not in stability when kT > 0.5. Its very important for modeling microscopic traffic flow model. In this paper there are shown that microscopic traffic flow in K. Mindaugo – Birštono streets has Puasson distribution. There are made microscopic traffic flow simulation model of K. Mindaugo – Birštno streets crossroad by Arena 3.0 program and performed regression analysis for prognosticating microscopic traffic flow queues.

The following main problems were solved in the research: • The factors negatively influencing the traffic safety system efficient interaction and reliability were identified. • Reliability of reaction calculations of the traffic participants. • Application of ANOVA in the research of the traffic participant’s reactions. • Application of the SAS software package in the research of the traffic accident causes. • Identification of factors influencing the formation of the traffic participant’s behaviour.

Šiame dokumente pateikiamas specializuoto grafinio redaktoriaus - kelių eismo įvykių registravimo programinės įrangos kūrimas. Dokumentą sudaro trys pagrindinės dalys: analitinė, projektinė ir vartotojo dokumentacija. Analitinėje dalyje sudarytas projekto kūrimo planas, apžvelgiami egzistuojantys sprendimai, apibrėžiami pagrindiniai reikalavimai kelių eismo įvykių schemų brėžimui. Projektinėje dalyje apibrėžiami funkciniai, nefunkciniai reikalavimai, panaudojimų atvejų modelis, pagrindinė bei detali architektūra. Vartotojo dokumentacijoje aprašomas programos naudojimas. / The development of specialized graphic editor - traffic accident graphic registration software is considered in this paper. The document consists of three main segments: analytic, designing and user documentation. Analytic part includes a project development plan, an overview of existing accident reconstruction software, main requirements for drawing traffic accident schemes. Designing part includes functional, non functional requirements, use case model, main and elaborate architecture of the project. User documentation describes the usage of the created software.

Šiame darbe nagrinėjama eismo saugumo politika Lietuvoje ir jos įgyvendinimo veiksmingumas. Santykinai avaringumo rodikliai Lietuvoje keletą kartų blogesni nei kitose išsivysčiusiose šalyse. Statistikos duomenimis, per metus Lietuvos keliuose žūva 700-800 žmonių. Europos Sąjungoje mirčių eismo įvykiuose skaičių sumažėjo 17 proc., tačiau Lietuvoje jų padaugėjo beveik 8 proc., todėl darbe analizuojamas eismo saugumo politikos įgyvendinimas, gilinamasi į šios politikos neveiksmingumo priežastis. Teorinėje dalyje aprašomas darbe taikomas G. Morgan teorinis pagrindas, išskiriamos galimos įgyvendinimo nesėkmės priežastys. Antrojoje, empirinėje dalyje taikomas tyrimo būdas – atvejo analizė. Analizuojama eismo saugumo politika Lietuvoje, tiriama, ar G. Morgan išskiriamos nesėkmingo įgyvendinimo priežastys egzistuoja Lietuvos atveju. / The object of this study – reasons for road safety policy implementation failure. The main purpose of master study – to clarify the reasons of inefficient implementation of road safety policy in Lithuania. Main goals of this study are as follows: to analyze G. Morgan theory and indentify presumable reasons for implementation failure; to verify, do these reasons for implementation failure exist in Lithuanian road safety policy. There are plenty of organizations, which are responsible for road safety policy implementation In Lithuania, but still, road safety situation does not improve. Decisions are made by Government, ministries, departments, but there is no one coordinating institution, which is responsible for road safety. Consequently the hypothesis of master study is that inefficient implementation of road safety policy in Lithuania is determined by disarray inside institutional system. The problems in institution system: non-existence of coordination and control and organizational unity, ineffective change management and incapacity to adapt, inappropriate organizational structure, ineffective human resource management. The main question of analysis - which problems of institutional system determine inefficient road safety policy in Lithuania? Ineffective change management is one of the most significant reasons, why the road safety policy is inefficient in Lithuania. A permanent observation of environment and capacity to adapt are necessary for effective change management... [to full text]

Child road safety education is one of the special aims for the comprehensive school. The education is one of the strategies of the traffic safety. Pedestrians are the most vulnerable category of traffic participants. Lithuania distinguishes by the biggest number of injuries of the pedestrians during accidents among other European countries. Considering the fact that formal obeying to the road traffic rules doesn’t guarantee the safety of the pedestrians, the most dangerous place for the pedestrian is the zebra crossing. Safe pedestrian traffic on the motor roads even formally obeying the Road Traffic Rules requires certain competence of road safety. People – pedestrians, their abilities to move safely in the dangerous environment of the motor road traffic are the most important factor in securing the safety of pedestrians. As demonstrated by the experience of other European countries safe traffic education programs that are being implemented in development practice are characterized by low efficiency when the change of the pupils’ behaviour in a real street is thought as the effectiveness of the education. The subject of the present dissertation is the development of child pedestrian road safety competence in the primary school. The goal of the dissertation is to reveal the situation of development of child road safety competence, to disclose the assumptions for road safety education in the primary school and their improvement, to interpret these assumptions theoretically... [to full text]

The purpose of the work is to analyze road safety and the quality of illumination in Akademija town, suggest the means for improving it. In the work there is car accidents in Lithuania and the town of Akademija analized; it was discovered, that in the period of 1980 – 2005 in the car accidents, 20637 people died and 14801 were injured. Since 2001, accident rate have been increased as the number of new cars and traffic flows is rising every day. Approximately 40 % of traffic accidents happen in the dark period of the day, and 70% of pedestrians, participating in the event, die. Traffic safety mostly depends on the level of illumination. In Akedemija town were fixed 142 traffic events, during last four years. There were injured 28 persons. The analysis for road illumination improvements was done and the illumination of the Akademija streets was observed. There are three streets in the area of Akademija and Ringaudai, illuminated enough, Mokyklos, Pilėnų and Tako (6 lx). Not enough there are lighted Student street and Pedestrian pathway between Akademija and Ringaudai. The worst situation is in the Universiteto Street. The illumination near the 5th dormitory hardly reaches 2.4 lx, and there is 4.5 lx illumination near the 6th dormitory. A part of Universiteto street is not lighted up at all. According to the requirements, with the help of computer program „Calculux road 6.2.2“, there is illumination of Akademija town designed and the economical evaluation done. The cost of... [to full text]