Original scientific paper Planning of road transport infrastructure is a complex process. One of the major issues is determining the design elements of road infrastructure (road type and number of traffic lanes, cross-sectional profile, etc.). When designing roads, parameters from the international literature are used, containing values derived empirically from local data on traffic flow (mostly from northern American cities). The goal of this paper was to explore traffic flows for the purpose of developing a model that will enable scientifically exact description of traffic flows in urban areas of Central Europe. Study of basic parameters of traffic flow included the selection of road location, survey time, traffic survey, analysis of video recordings, as well as statistical analysis and calculation of basic parameters of traffic flow. Added value of this research is demonstrated through the method of collecting and analysing the data for each lane (or roadway) separately in order to detect the difference in the values of the basic parameters of traffic flows. The research was conducted on various urban roads and in various traffic conditions and in this way the basic parameters of traffic flow were obtained. These parameters were used to develop diagrams of relations between speed, traffic density and volume, resulting in cumulative functions of traffic flow parameters for the entire urban traffic network. This made it possible to develop new equations enabling theoretical determination of flow volume, speed and density for a given road. Methods established in this work and the results of the research present a useful and applicable tool for benchmarking road capacity and finding relevant coefficients significant for dimensioning the road cross-sections in urban areas, but also on all other categories of roads. Keywords: density and volume; road infrastructure design; road network; traffic flow; traffic modelling; traffic speed Modeliranje prometnog toka na prometnoj mreži u gradovimaIzvorni znanstveni članak Planiranje cestovne prometne infrastrukture je složen proces. Jedan od najvećih problema je određivanje projektnih elemenata cestovne infrastrukture (vrsta ceste i broj prometnih traka, poprečni profil i sl). Za potrebe dimenzioniranja prometnica koriste se parametri iz strane literature s vrijednostima koje su empirijskim metodama derivirane iz lokalnih podataka o prometnom toku (najčešće sjevernoamerički gradovi). Cilj ovog rada bio je istraživanje prometnih tokova radi izrade modela koji će pružiti mogućnost egzaktnijeg opisa lokalnih karakteristika prometnih tokova na području srednjoeuropskih gradova. Istraživanje osnovnih parametara prometnog toka sastojalo se od izbora lokacije cesta, vremena snimanja, snimanja prometa, analize video zapisa istatističke analize i proračuna osnovnih parametara prometnog toka. Posebnost provedenog istraživanja sadržana je u načinu prikupljanja i analizi podataka za svaki prometni trak (ili kolnik) radi uočavanja razlike u vrijednostima osnovnih parametara prometnih t...

One of the measures to increase road traffic safety in Croatia is the introduction of obligatory use of daily lights on vehicles in road traffic during driving, regardless of the visibility and the time of day. The paper describes the new original technical and technological procedure of analysing automotive light bulbs in order to find the traces of glass particles of the broken glass balloon in the marginal cases of action of small inertia forces generated as result of a traffic accident. Investigations of light bulbs in traffic accidents had been rarely done before; therefore the subject of this scientific research is the analysis of the light bulb filament used in automobiles to light the road ahead and to give light signals, i.e. all the light signalling devices on the automobile using the new technical and technological procedure by means of SEM/EDX method. The scientific research has improved the investigation procedure in analysing the light bulbs on automobiles in determining whether at the moment of the traffic accident the regulatory lights were switched on. In determining the responsibility of participants for causing the traffic accident, such a fact may sometimes be of crucial significance. KEY WORDS: traffic accident, light bulb, technical and technological procedure, lights in traffic, microscope, molten glass particles

In the year 2007, it has been statistically noted, that the number of persons living in the cities has exceeded 50% globally. In accordance with this trend of growth of city residents, by the year 2030, 6 out of 10 people will be living in the cities and this number will increase to 7 out of 10 by the year 2050. The questions of optimal functioning, sustainable growth and quality of urban life are now more important than ever and the city traffic system has a crucial role in it. The optimal contribution of the city's traffic system in the functioning and development of the city, especially with the expansion of its population, is only possible by acquiring the technical, technological, organizational and compatibility and complementarity of the transport systems in supplying the demand for transport.  Index Terms-city traffic system, compatibility, complementarity of the transport systems, growth, development