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Urban traffic congestion is a significant problem for almost every city, affecting various aspects of life. Besides increasing travel time, congestion also affects air and life quality causing economic losses. The construction of infrastructure to solve congestion problems is not always feasible, and, at the end, attracts only additional traffic demand. Thus, a better approach for solving the problem of city congestion is by optimal management of the existing infrastructure. Timely detection of traffic congestion on the road level can prevent congestion formation and even improve road network capacity when used for appropriate traffic control actions. Detecting congestion is a complex process that depends on available traffic data. In this paper, for traffic state estimation, including congestion level, at the intersection level, a new method based on Speed Transition Matrix and Fuzzy-Based System is presented. The proposed method utilizes the Connected Vehicle environment. It is tested on a model of an isolated intersection made in SUMO simulation software based on real-world traffic data. The validation results confirm the successful detection of traffic state (congestion level) at intersections.

Intelligent Transportation Systems (ITS) offer a solution for alleviating congestion in urban areas based on its traffic control service. It is part of the build + ITS approach where new infrastructure with different ITS services is applied to improve traffic throughput, reduce vehicle emissions, increase the Level of Service (LoS), and improve the usage of existing vehicles with the Mobility as a Service (MaaS) concept. The latter enables the cities to offer mobility users concepts of car-sharing, ride-sharing, and tailored multi-modal travel patterns. The city or urban road infrastructure can be divided into urban motorways and networks of signalized intersections. Traffic control approaches related to Variable Speed Limit (VSL) control, ramp metering, lane change recommendation, and Adaptive Traffic Signal Control (ATSC) are applied to manage the urban road infrastructure.

The rapid increase in the number of vehicles on the roads is attracting the attention of many researchers around the world. The consequences of the increased number of vehicles are numerous, firstly increased congestion and negative climate effects, and secondly, many countries and companies are encouraged to research traffic behavior and collect historical data from traffic sensors. Simulations are gaining a significant role in researching traffic characteristics, as not all scenarios are feasible in the reality. Observing traffic in simulation environments provides a significant number of parameters that can be obtained and analyzed. In this paper, we provide an overview of the process of creating traffic simulations in the SUMO simulator. In addition, we have managed to automate part of the process of preparing the simulation.

One of the most effective ways to prevent traffic accidents is to identify and repair hazardous sites in the road transport network. In the Republic of Croatia from 2004 to 2016, the methodology for identifying hazardous sites based on a numerical definition was used, and in January 2017, a new methodology based on the statistical examination of each location of traffic accidents was adopted and it was fully aligned with international experience and recommendations. International experience shows that the most relevant results in identifying hazardous sites are achieved through an immediate overview of the location of traffic accidents on the ground. However, as about 5000 different traffic accidents occur on state roads on a yearly basis, it is clear that for objective reasons they can not all personally review, it is necessary, based on collected data on traffic accidents and traffic loads, to identify the locations of traffic accidents that pose a potentially dangerous places. For this purpose, this paper will outline the process of identifying potentially hazardous sites that need to be analyzed on-site in order to reach a final assessment of whether it is really a dangerous place where remedial measures can reduce the number of traffic accidents. This conceptualized process of identifying dangerous places allows for the cancellation of so-called " false hazardous sites that only occur periodically due to heavy traffic loads, and are not conditioned by road traffic-technical shortcomings.

Postupak valnog multipleksiranja značajno povećava kapacitet optičkog vlakna. Kod svjetlovodnih prijenosnih sustava razlikuju se CWDM i DWDM izvedba, a svaka izvedba zahtjeva određene komponente za ostvarenje prijenosa signala. Uz optičko vlakno kao osnovnu komponentu, ključne komponente su: optički prospojnik, optički predajnici i prijemnici, multipleksori, optički filtri i pojačala. Cilj ovoga rada je opisati postupke valnog multipleksiranja, potrebne komponente i tehnologije za funkcioniranje optičke mreže te su analizirani i mehanizmi zaštite u ovisnosti o topologiji mreže kao i arhitektura WDM mreže.

Traffic safety is one of the key demands in the traffic system, and one of the main indicators of safety conditions in traffic system is amount of traffic accidents and their repercussions. Taking in the mind that highways are considered as the safest among all roads in the view of many traffic and technical parameters, it is necessary to investigate road traffic safety of state roads in the Republic of Croatia more closely, especially when considered that many of the state roads have higher traffic density than highways. High amount of traffic accidents on some road is not relevant parameter for identifying that road like the hazardous one, so in the paper hazardous roads are identified and classified considering their traffic and technical parameters, such as road length, traffic demand on the road and amount of traffic accidents on the road, using Rate Quality Control method. According to this methodology, it is possible to detect some “hidden” hazardous state roads, and it is possible to detect hazardous roads which have never been in the primary focus of road traffic safety investigation.

Izrada prometnog djela prostorno planske dokumentacije je vrlo važan proces prostorne integracije određene zone obuhvata. U Republici Hrvatskoj za izradu iste u projektnom timu mora biti angažiran prometni ili građevinski stručnjak koji snosi moralnu i stručnu odgovornost za svoje djelo prilikom čega ne postoje nikakvi drugi uvjeti za izradu prometnog djela prostornog plana. Kao posljedica toga dolazi do nerijetke implementacije prometnica koje nemaju svoju primarnu funkciju prostorne integracije već dovode do društvenih gubitaka. Provođenjem RSIA postupka (Road Safety Impact Assessment) u sklopu Direktive 2008/96/EC o sigurnosti cestovne infrastrukture bi se već u fazi prometnog planiranja, tj. izrade prostorno planske dokumentacije, stvorila stručna prometna podloga za kreiranje prometno optimalnog rješenja trase, prometnice. Takvo prometno planiranje rezultiralo bi kvalitetnijim prostornim planovima te bi se izbjegla implementacija loših prometnih rješenja, a u konačnici bi se i povećala sigurnost

Procjena sigurnosti prometa u fazi planiranja i projektiranja cesta prema europskoj direktivi o sigurnosti cestovne infrastrukture.

The Greater Alpine Region (the GAR) covering the area between 4-19°E and 43-50°N and and altitude range between = and more than 4000 m asl. offers a challenging climate worth to be studied in any detail. However, it is surprising that up to now no comprehensive Alpine Temperature Climatology covering the whole region is existing. To overcome this deficiency as a first step we want to produce monthly temperature maps for this region in spatial resolution as high as possible. The period under investigation will be 1961-1990. In this paper we will describe the first steps of our initiative as well as further plans.

Statistički podaci ugroženosti u cestovnom prometu ukazuju na činjenicu kako su pojedine kategorije sudionika prometa više ugoržene u odnosu na druge. Za područje Hrvatske, karakteristično je potenciranje činjenice kako je skupina u koju se ubrajaju djeca i mladi, osobito ugrožena u cestovnom prometu. Međutim, u radu se, temeljem provedene analize statističkih podataka u prometnim nesrećama, ukazuje i na neke druge kategorije sudionika, za koje je karakteristična povećana incidentnost. Paralelno s navedenim daje se komparativni prikaz sa sličnim pokazateljima razvijene države zapada kao i prijedlog mogućih smjerova preventivnog djelovanja.

Harmonization in the area of traffic signalizatio.

Prometne nesreće predstavljaju uzrok najvećeg broja stradanja ljudi suvremenog svijeta. Polazeće od činjenice da sve države suvremenog svijeta imaju razvijene sustave statističkog praćenja i analize prometnih nesreća, postavlja se pitanje kako takav sustav u što većoj mjeri iskoristiti za identifikaciju i otklanjanje uzroka prometnih nesreća. Jedan od temeljnih preduvjeta za učinkovito korištenje statističkih analiza u preventivne svrhe je vezanje statističkih podataka za konkretna lokacijska mjesta. U radu su prikazani dosezi lokacijskih analiza statističkih podataka o prometnim nesrećama RH. Na temelju rezultata statističkih analiza, zahtjevanih lokacijskih distribucija koje imaju konkretnu uporabnu vrijednost, te značajki suvremene tehnologije koja se koristi za geografsku lokaciju, dati su prijedlozi za rješavanje konkretnih problema koji će omogućiti uvođenje GPS sustava u sustav statističkog praćenja prometnih nesreća.

Das Klimaelement Niederschlag zeigt auf allen der raum-zeitlichen Skalen starke Variabilität, auch im langfristigen Trendverhalten. Ein neuer, räumlich dichter Datensatz von 192 homogenisierten instrumentellen Reihen in monatlicher Auflösung im Großraum Alpen wird hier vorgestellt , der bis zum Jahr 1800 zurückreicht. Erste Analysen deuten auf eine systematische Langfrist-Oszillation zwischen gegenläufigen Trends NW-lich und SE-lich der Alpen hin.