Brzina slobodnog toka se kao parametar koristi u modelima transportnog planiranja, modelima analize kapaciteta cestovnih prometnica kao i u izradi dijagrama brzina-tok. Značajan broj razvijenih modela ne koristi procedure za procjenu brzine slobodnog toka već predlaže da se brzina slobodnog toka procijeni usporedbom sa zabilježenim brzinama slobodnog toka na sličnim već izgrađenim prometnicama što predstavlja značajan problem, a naročito na području Bosne i Hercegovine. U ovom radu se u prvom dijelu analiziraju problemi upotrebe postojećih modela u uvjetima prometa i prometnica u B&H, a u drugom se prikazuje model za procjenu brzine slobodnog toka razvijen na temelju opsežnog terenskog istraživanja provedenog na 9 homogenih dionica državnih i regionalnih cesta.

Recently, Variable Message Signs (VMS) were introduced in Saudi Arabia and their reliability under local environment is being tested. This paper aims to evaluate the possible response of the drivers to VMS when used for messages related to traffic conditions. A major arterial in Al-Khobar city in Saudi Arabia with a massive VMS board was selected for this paper. The evaluation process started by interviewing drivers selected randomly from the study area. About 77% of the interviewed drivers indicated positive attitude toward messages requesting change of route. The drivers’ interviews demonstrated statistical relationship between the degree of response to messages requesting change of route and the reason for such request. The maximum response was for messages related to accidents, roadwork activities, and traffic congestion. A field experiment was also conducted along the studied arterial. It was found that VMS statistically increased the percentage of diverted traffic during specific peak periods.

The basic principle of optimal traffic control is the appropriate real-time response to dynamic traffic flow changes. Signal plan efficiency depends on a large number of input parameters. An actuated signal system can adjust very well to traffic conditions, but cannot fully adjust to stochastic traffic volume oscillation. Due to the complexity of the problem analytical methods are not applicable for use in real time, therefore the purpose of this paper is to introduce heuristic method suitable for traffic light optimization in real time. With the evolution of artificial intelligence new possibilities for solving complex problems have been introduced. The goal of this paper is to demonstrate that the use of the Q learning algorithm for traffic lights optimization is suitable. The Q learning algorithm was verified on a road artery with three intersections. For estimation of the effectiveness and efficiency of the proposed algorithm comparison with an actuated signal plan was carried out. The results (average delay per vehicle and the number of vehicles that left road network) show that Q learning algorithm outperforms the actuated signal controllers. The proposed algorithm converges to the minimal delay per vehicle regardless of the stochastic nature of traffic. In this research the impact of the model parameters (learning rate, exploration rate, influence of communication between agents and reward type) on algorithm effectiveness were analysed as well.

Traffic is the most significant noise source in urban areas. The village of Kamenari in Boka Kotorska Bay is a site where, in a relatively small area, road traffic and sea (ferry) traffic take place at the same time. Due to the specificity of the location, i.e. very rare synergy of sound effects of road and sea traffic in the urban area, as well as the expressed need for assessment of noise level in a simple and quick way, a research was conducted, using empirical methods and statistical analysis methods, which led to the creation of acoustic model for the assessment of equivalent noise level (Leq). The developed model for noise assessment in the Village of Kamenari in Boka Kotorska Bay quite realistically provides data on possible noise levels at the observed site, with very little deviations in relation to empirically obtained values.

Reducing car trips and promoting green commuting modes are generally considered important solutions to reduce the increase of energy consumption and transportation CO2 emissions. One potential solution for alleviating transportation CO2 emissions has been to identify a role for the employer through green commuter programs. This paper offers an approach to assess the effects of employer attitudes towards green commuting plans on commuter mode choice and the intermediary role car ownership plays in the mode choice decision process. A mixed method which extends the traditional discrete choice model by incorporating latent variables and mediating variables with a structure equation model was used to better understand the commuter mode choice behaviour. The empirical data were selected from Washington-Baltimore Regional Household Travel Survey in 2007-2008, including all the trips from home to workplace during the morning hours. The model parameters were estimated using the simultaneous estimation approach and the integrated model turns out to be superior to the traditional multinomial logit (MNL) model accounting for the impact of employer attitudes towards green commuting. The direct and indirect effects of socio-demographic attributes and employer attitudes towards green commuting were estimated. Through the structural equation modelling with mediating variable, this approach confirmed the intermediary nature of car ownership in the choice process. The results found in this paper provide helpful information for transportation and planning policymakers to test the transportation and planning policies effects and encourage green commuting reducing transportation CO2 emissions.

Investment in the transport system with the aim of fostering attractiveness and land use in urban structures is of great interest for planners and investors. Investment in urban public transport would especially contribute to revitalising distinct city areas. The samples of high population density and diversified area use are organised around accessible means of urban public transport.

The theoretical assumption on the influence of better organised transport on land use is hereby researched through the example of correction of timetables and reduction of travelling time between nodes on the line in the Novi Jelkovec settlement. In preparing this paper the following methods were used: analysis and synthesis, mathematical and statistical methods, methods of interviewing. The theory of correlation of land use and urban public transport is based on models that develop the “compact city”.