No abstract

Efficiency of road works is conditioned by selection of machines and synchronizing their operations. Modelling these works using queuing theory allows the planner to conduct an in-depth analysis of the system’s operation to find the best machine types and their optimal number. For simple cases, analytic formulas are used to calculate such parameters as a probability of a server’s standing idle, average length of a queue, or average waiting time. However, complex real-life systems are to be analyzed more efficiently by means of simulations. The paper presents simulation model of a road repaving project. Using it, the authors evaluated the economic effect and output of the system served by different machine sets. Applying a number of additional optimization criteria (cost, productivity, machine utilization rates, etc.) the authors were able to find most suitable machine sets.

The aim of the conducted research was to assess the effectiveness of the applied solutions for reducing traffic noise, using the tramline in Bydgoszcz (the largest new tramline in Poland in the last 25 years) as an example. The research of traffic noise was carried out during both the execution of the investment in 2014 and the assembly of noise barriers in 2015, as well as after launching tram traffic in 2016. Measurements of the intensity and type structure of road traffic were made. The results of on-site measurements were compared to the standard permissible values of traffic noise and also to guidelines about the scale of traffic noise nuisance, which were developed by the National Institute of Hygiene. The effectiveness of the used acoustic barriers and their impact on the acoustic comfort for users of the road environment, mainly residents of multi-family buildings, were verified. Based on the carried out measurements, a high efficiency of the applied acoustic barriers, which caused a reduction of sound level by approximately 10 dB(A) was proved.