This article aims to identify potential risk factors affecting the implementation and synchronisation of surveying and construction works during building and operation of roads. The task was executed on the basis of literature studies and experience. The article is an introduction to the research that has been conducted by the authors on the reasonably precise index of factors which one may deal with during the implementation of facilities of this type. The raised issue is crucial for financial and time reasons, but what is important in the roads construction - also for social ones, as prolonged traffic disruption adversely affects the environment.

In the paper methods for conducting Road Safety Inspections (SIs) in Italy and Poland are described and compared. The goal of the study is to improve the quality and efficiency of the safety inspections of road network by using low cost equipment (GPS, Tablet, Camera) and specific software. Particular attention was paid to the need for proper calibration of factors, causing traffic safety hazard associated with road infrastructure. The model developed according to the Italian procedures was adapted to comply with the checklists and evaluation criteria of the Polish guidelines. Overall, a good agreement between the two approaches was identified, however some modification was required to include new safety issues, characteristic for the Polish network for safety inspection of two lane rural roads. To test the applicability about 100 km of regional two lane roads in Poland were inspected with Polish and Italian procedures.

U-turn lanes eliminate left turns at intersections and allow the manoeuvre to be made via median crossovers beyond the intersection. However, there are many situations where road infrastructures are characterized by the reduced width of the median. It is clear that, in such situations, we must adopt design criteria that take into account limitations imposed by the width of the cross-section of the road. This is the reason why it is necessary to adopt design solutions which expect a complete reorganization of the road section affected by the insertion of U-turns. In this paper, we intend to propose original guidelines for U-turn lane design, suitable to guarantee both the necessity to offer a high level of functionality of the road sections to be implemented by U-turns, and the principles of safety in order to reduce unsafe conditions during inversion manoeuvres as much as possible.

The sound radiation from vehicles travelling on the city roads with T junction was considered. The wind effect on acoustic field was taken into account. The solution of this problem was found with the help of the integral Fourier transforms and stationary phase method as the superposition of solutions for the cases of vehicles moving along the straight roads and roads with right-angle bend. As an example, the numerical analysis of traffic noise characteristics was carried out for the T junction city road on one of streets in the town of Łodź (Poland).

One of the basic parameters which describes road traffic is Annual Average Daily Traffic (AADT). Its accurate determination is possible only on the basis of data from the continuous measurement of traffic. However, such data for most road sections is unavailable, so AADT must be determined on the basis of short periods of random measurements. This article presents different methods of estimating AADT on the basis of daily traffic (VOL), and includes the traditional Factor Approach, developed Regression Models and Artificial Neural Network models. As explanatory variables, quantitative variables (VOL and the share of heavy vehicles) as well as qualitative variables (day of the week, month, level of AADT, the cross-section, road class, nature of the area, spatial linking, region of Poland and the nature of traffic patterns) were used. Based on comparisons of the presented methods, the Factor Approach was identified as the most useful.

Many of already existing roads cross wetland river valleys. Also the roads nowadays planned are cutting through valuable wetlands. It is necessary to evaluate the range of their impact on the natural environment. This paper focuses only on the analysis of the road crossing impact on the groundwater level. Two options of crossing the wetlands were analyzed, building the road on embankments and in the bridge. It was assumed that the valley is filled with organic material under laid by permeable sands. Calculation results showed that building a road in the valley affects groundwater level only to the slight extend. Water conditions in the valley may be affected only during the construction of the road. Calculation results were confirmed by field observations.

It should be stressed that the object of this paper is the evaluation of water conditions. Environment might be influenced by other factors.

Acoustic barriers which are positioned along traffic lanes are designed to protect the surroundings from excessive noise. Such structures are to reverberate, diffract and damp the propagating acoustic waves. However, this method of shielding has some disadvantages which include constraint visibility and structure-born noise. The interaction between traffic-caused movement of air mass and acoustic barriers may generate infra noise waves. That is undesirable and should be estimated. The authors undertook the research to diagnose the plausible side effect of structure-born noise of such barriers because it may influence human body (Kasprzak, 2014). As a mechanical structure, the acoustic barrier is characterized by mechanical parameters which, in the field of modal analysis, are made up of natural frequencies, damping factors and mode shapes. In this paper the authors investigated the acoustic pressure distribution in the neighborhood of a real acoustic barrier in the scope of infra noise propagation. The methods of modal analysis were used to identify natural frequencies of the barrier and dominating frequencies of propagating waves in the far field. The correlation between observed vibration and acoustic signals is presented.