Traffic flow modelling on the road network in the cities

• Published in: Tehnički vjesnik Vol. 22; no. 2; pp. 475 - 486
• Main Author: Horvat, Rajko
• Format: Journal Article
• Language: English
• Published: 01-04-2015
• Subjects: Density; Lanes; Mathematical models; Networks; Roads; Traffic engineering; Traffic flow; Urban areas
• ISSN: 1330-3651; 1848-6339
• DOI: 10.17559/TV-20150127093334

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.Original Abstract: Planiranje cestovne prometne infrastrukture je slozen proces. Jedan od najvecih problema je odredivanje projektnih elemenata cestovne infrastrukture (vrsta ceste i broj prometnih traka, poprecni 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 (najcesce sjevernoamericki gradovi). Cilj ovog rada bio je istrazivanje prometnih tokova radi izrade modela koji ce pruziti mogucnost egzaktnijeg opisa lokalnih karakteristika prometnih tokova na podrucju srednjoeuropskih gradova. Istrazivanje osnovnih parametara prometnog toka sastojalo se od izbora lokacije cesta, vremena snimanja, snimanja prometa, analize video zapisa istatisticke analize i proracuna osnovnih parametara prometnog toka. Posebnost provedenog istrazivanja sadrzana je u nacinu prikupljanja i analizi podataka za svaki prometni trak (ili kolnik) radi uocavanja razlike u vrijednostima osnovnih parametara prometnih tokova. Istrazivanje je obavljeno na razlicitim gradskim prometnicama i u razlicitim prometnim uvjetima te su dobiveni osnovni parametri prometnog toka. Pomocu tih parametara napravljeni su dijagrami odnosa brzine, gustoce i propusne moci i dobivene su kumulativne funkcije parametara prometnih tokova za cjelokupnu prometnu mrezu grada. Time je omoguceno da se izrade nove jednadzbe pomocu kojih je moguce teoretski odrediti kapacitet, brzinu i gustocu toka prometnice. Razvijena metoda kao i rezultat ovog znanstvenog istrazivanja pouzdan je, koristan i primjenljiv alat za odredivanje kriterija propusne moci ceste i proracun vrijednosti relevantnih koeficijenata mjerodavnih za dimenzioniranje poprecnog presjeka cesta u urbanim sredinama, ali i svih ostalih kategorija cesta.