The requirements imposed on road pavements are ever increasing nowadays, necessitating the improvement of the properties of paving materials. The most commonly used paving materials include bituminous mixtures that are composed of aggregate grains bound by a bituminous binder. The properties of bitumens can be improved by modification with polymers. Among the copolymers used for modifying bitumens, styrene–butadiene–styrene, a thermoplastic elastomer, is the most commonly used. This article presents the results of tests conducted on bitumens modified with two types of styrene–butadiene–styrene copolymer (linear and radial). Two bitumen types of different penetration grades (35/50 and 160/220) were used in the experiments. The content of styrene–butadiene–styrene added to the bitumen varied between 1% and 6%. The results of the force ductility test showed that cohesion energy can be used for qualitative evaluation of the efficiency of modification of bitumen with styrene–butadiene–styrene copolymer. The determined values of the cohesion energy were subjected to the original analysis taking into account the three characteristic elongation zones of the tested binders. The performed analyses made it possible to find a parameter whose values correlate significantly with the content of styrene–butadiene–styrene copolymer in the modified bitumen. With smaller amounts of added modifier (approximately 2%), slightly better effects were obtained in the case of linear copolymer styrene–butadiene–styrene and for larger amounts of modifier (5–6%) radial copolymer styrene–butadiene–styrene was found to be more effective. This is confirmed by the changes in the binder structure, as indicated by the penetration index (PI).

Various additives to asphalt binders and asphalt mixtures improving their properties are being used more and more frequently in order to improve the durability of road pavements. Such additives include various types of fibres, including aramid fibres. Tests concerning the impact of aramid fibre addition on the properties of selected asphalt mixtures have been described herein. Two types of asphalt mixtures were assessed: high modulus asphalt concrete (HMAC) and stone mastic asphalt (SMA). The examined asphalt mixtures were assessed with regard to: resistance to rutting, resistance to water and frost as well as fatigue resistance. The conducted tests showed relatively small impact of aramid fibre addition on the improvement of some assessed properties of the analysed asphalt mixtures. The obtained results were also compared to results of the tests conducted by the other research team concerning the impact of aramid fibre addition on the properties of the other types of asphalt mixtures.

The purpose of the study was to test the level of respecting the speed limit by drivers of vehicles in a traffic-calming zone that was not formally designated, located in a part of an old city in a middle of the Polish city. Due to the historic assets in that location, the applied means of traffic calming included only legal-organizational means, i.e. local speed limit signs. The analysis was carried out of vehicles speed in selected measuring sections; next, the level of respecting speed limits by drivers was determined. The results proved that just installing the speed limit signs at entrances to zones or at priority to the right intersections are insufficient to obtain the required speeds. The tests revealed that in all tested sections, drivers exceeded the speed limit of 30 km/h. An average speed varied from 32.1 km/h to 37.1 km/h, with the 85% quantile of speed amounting from 36.1 km/h to 42.7 km/h. A large percentage of drivers who exceed the speed limit was recorded, which was from 35% to 90%. The lowest percentage of drivers exceeding the maximum speed was recorded in sections where the surface was made of cobblestone (only 10%). This stemmed from the fact that in order to obtain the driving comfort, the drivers were forced to reduce the speed significantly. The results of tests show explicitly that in order to obtain desired traffic conditions from the safety perspective, it is necessary to apply physical means of traffic calming that force drivers to reduce speed. Such measures should include: an adjustment of the traffic corridor geometry in a general layout, narrowing a lane, speed bumps, raised speed tables at intersections, and raised pedestrian crossings. The applied traffic calming measures, including but not limited to areas that are subjects to the conserver’s supervision, should meet high functional, engineering, and visual standards, and be a harmonious part of the historic surrounding.

Transport models are mathematical tools necessary for many transport analyses. They are applicable among others in economic analyses, and especially in the development of feasibility studies. One of the key elements of such models is their credibility, which results from good technical assumptions. Important information is undoubtedly information about the spatial development of the area under investigation. Much data on the attractiveness of particular areas, so-called transport zones, needs to be collected when constructing a transport model for urban areas. The paper presents the ways of obtaining and aggregating data to determine measures of transport zones attractiveness for daily trips in the example of Bydgoszcz and Toruń.