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Interventions to road are always required to keep road network in a good condition for this reason road works such as maintenance or reconstruction are carried out regularly. Roadwork zone distorts typical driving conditions and brings many unknown factors to driving process that increase the likelihood of an accident or congestion formation. Roadworks zones in Lithuania are a serious problem due to congestion formation, therefore, before the real construction works, it is necessary to carry out traffic flow and capacity modeling as well as to choose the appropriate traffic organization scheme through roadworks zones. The biggest congestion of vehicles in Lithuania occurs in roadworks zones where there is one lane left and traffic is controlled by traffic light, which do not adapt to real traffic conditions, but operate according to the created cycle and frequency model. The simulation analysis of roadwork zone with temporary traffic lights, in order to select optimal green light cycle and frequency is represented, in this paper. DOI: https://doi.org/10.3846/enviro.2020.672

Tire/pavement noise is one of the biggest environmental problems caused by the contact between the car tire and the pavement surface. It is known that porous asphalt (PA) pavements has good properties in noise absorption, however these mixtures could also solve another important problem which appear on roads – aquaplaning. This phenomenon reduces traffic safety and driving comfort. Aquaplaning appears when tires become separated from the pavement surface by thin water film and the ability to increase braking force or control the vehicle motion is almost entirely lost. Although, PA pavements have relatively low durability properties. This research aims analyse surface texture and permeability characteristics of aquaplaning resistant asphalt pavements. Four different mixtures with different largest particle size (AT 5, AT 8, AT 11 and AT 16) were tested. Large-scale laboratory testing was performed to evaluate their surface texture and permeability properties The research revealed, that mixtures with 8 % activated mineral limestone powder (AMLP) showed better mechanical and physical properties than comparing to other mixtures with 4 % AMLP and 4 % granite screenings or just 4 % AMLP.

The application of low noise pavement is one of the most effective solutions to reduce tire/pavement noise. Low noise pavements are achieved by using asphalt mixtures with a high air void content (e.g. porous asphalt). However, these material have relatively low durability. Therefore, to ensure sufficient durability and long-term acoustic properties, low noise asphalt mixtures must be designed considering both acoustic and climatic conditions. The main objective of this study was to design four semi-dense asphalt mixtures (2 stone and mastic asphalt (SMA) mixtures and 2 asphalt mixtures for very thin layers (BBTM)) with increased air void contents (>10%) that absorb tire/pavement noise and are resistant to traffic and climate conditions. Large-scale laboratory testing was performed to evaluate the acoustic properties as well as the effects of traffic and climate conditions on the performance of the designed asphalt mixtures. These tests revealed that modified BBTM asphalt mixtures have better sound absorption properties than modified SMA mixtures but are less resistant to rutting, have lower stiffness and indirect tensile strengths and exhibit higher mass loss after freeze-thaw cycles. BBTM 5 which has the highest air void content (15.4%), had the highest (0.54) sound absorption coefficient of all the tested mixtures. The most promising asphalt mixture was identified by a developed analytic hierarchy (AHP). The BBTM 8 mixture is the most rational solution for low noise pavement.

Planned special events (PSE) every year attract many people to one place. After all, increased traffic volume cause congestions and has a negative impact on the economy by decreasing productivity and decreasing the quality of people’s lives. Nevertheless, environmental pollution increases with increasing traffic. The effects of traffic congestion on traffic safety, however are less obvious. Fatal accident risks are less common in traffic jams but the probability of severe rear end crashes is increased. Investigation of real case study in Lithuania has been made and results are discussed in this paper.

Due to the increased traffic flow, more and more roadwork zones are formed in highways. Accidents are a significant problem in all European countries in roadwork zones while noncompliance with speed limits is one of the major safety concerns. Therefore roadwork zones are critical places from the point of traffic safety view where the possibility to get into an accident is increased. Roadwork zones introduce deviations from regular travel situations, and appropriate speed is needed to assure that the driver navigates safely through the roadwork zone. This research focuses on speed measurement in road work zones and attempts to evaluate the effectiveness of safety measures on speed limit compliance.

Low noise asphalt pavements are being implemented more often in colder climate regions. However, main disadvantage of low noise pavements is sensitivity to severe climate conditions (freeze-thaw, large temperature fluctuations) resulting in shorter acoustical and structural lifetime. This paper presents research study which main focus was to analyse acoustical and structural properties ageing/degradation of optimized low noise asphalt mixtures (SMA 5 TM, SMA 8 TM and TMOA 5) and porous asphalt (PA 8) on the real trafficked road sections. In depth analysis of CPX noise levels, SPB noise levels and sound absorption measurements, performed multiple times in a 2 years’ period (after construction), is given and explained in the paper. Paper concludes with the acoustical and structural ageing trends for selected asphalt mixtures and recommendations for low noise asphalt pavements maintenance actions in order to extend their lifetime.

Road accidents are one of the leading causes of death in the world, particularly among young people. Excessive speed is one of the main risk factors in road traffic safety, increasing accident probability and affecting accident severity. Experimental research of the traffic calming measures allocation effect on the driving speed is presented in this paper. The research has been carried out on two aspects. The first one with respect to the mean speed and the second one regarding instantaneous speed. However, the paper is not only restricted by the above research. Standardized survey interview and questioning, a survey of public opinion, was carried out to find out the road users’ opinions about the need for traffic calming measures and speed control measures. Finally, the authors presented their insights and recommendations for the installation of speed humps and gateways and their optimum spacing.

One of the biggest problems of constantly growing transport sector is traffic safety. Innovative technologies are an effective tool to deal with the following issue. In order to ensure efficient and coordinated development of intelligent transport systems, it is essential to know their individual performance and impact on traffic safety. This article gives the summary of the effect of intelligent transport systems on road traffic safety. The aim of the research is to highlight intelligent transport systems and intelligent transport systems applications which have the greatest positive impact on traffic safety. To achieve this aim, meta-analysis of previous studies and analysis of experts interviews was carried out. The research consider the following thirteen driver support and control systems regarding their potentials to reduce the number of fatalities: average speed control system, stationary speed cameras, “Alcolock” ‒ application of drunk driver detection, “eCall” system, variable speed limit sign, red light violation detection cameras, forbidden maneuver detection system, vehicle identification system, variable message boards, intelligent road studs, incident detection system, weighin- motion system and seat belt control system.