The purpose of this work is to assess the impact of vehicle speed in the city on traffic safety. Signalized intersections are common places where traffic accidents are concentrated in large cities. Left turns are the most dangerous maneuvers at signalized intersections, so an investigation of actual speeds for left-turning cars was carried out. Observations were carried out using video filming.
   An analysis of the speed processing results at signalized intersections in Volgograd and Volzhsky showed that the smaller the turning radius, the lower the speed of turning left. The average turning speed with a radius of 23 to 40 m for cars was 21,4-26,4 km/h, for trucks – 19,2-21 km/h. The average speed of left turns at signalized intersections is taken into account when calculating meantime of cycles. In Russia, the recommended average speed is 25 km/h. In Germany, the design speed of cars turning left depends on the turning radius – 18 km/h with a radius of less than 10m and 25 km/h with a radius of more than 10m. The actual average speed of left turns, as observed, can be both higher and lower than the Russian recommendations. The lower the speed of cars turning left and the larger the signalized intersection, the longer it takes for the car to travel long-distance conflict points. If time is not enough, there is a high probability of a traffic accident. To improve road safety at such complex nodes of the city’s road network as signalized intersections, it is necessary to detail the incoming parameters for managing transport and pedestrian flows.

   The article deals with the issues of improving the interaction of participants in the transport process when using information and reference systems. This topic was developed after the changes, that have occurred in communication networks over the past ten years. Namely, the transition from the construction of information and reference services on the basis of circuit-switched networks to packet-switched networks that implement IP-technologies The emerging features that fundamentally improve the quality of customer service of Russian Railways on the basis of the proposed methods were taken into account. automation and digitalization arising from the application of artificial intelligence. Weaknesses in granting access identified in the work through the packet switching network to the node of information and reference services. The conditions for the trouble-free operation of reference nodes are given. Under which subscribers do not receive a refusal to service their applications, which must be performed when organizing the interaction of participants in the transport process.
   The purpose of this study is to determine the optimal parameters of the communication network, at which trouble-free service to subscribers will be ensured. Particular attention in the article is paid to the issue of harmonizing the intensity of the load. When using artificial intelligence, which makes it possible to link transport and organizational interaction in information and reference systems, allows you to reduce the time of transactions, increase the speed of accepting applications from all participants in the process, increases the speed of transmission of responses and data transfer for organizational and management decisions.

   Since the creation of rail transport, one of the main ways to master the increasing volume of traffic has been a systematic increase in the average weight of freight trains. This value is limited by the useful length of the station tracks, the power of train locomotives, and the structure of cargo flows showing the weight of cars with cargo per one linear meter of the train. Given these conditions, for a long time, an increase in the average weight of freight trains was obtained by lengthening station tracks, introducing four-axle wagons with increased load capacity (compared to two-axle ones), replacing the screw coupling of wagons, generally accepted at that time, with automatic coupling. The article establishes the influence of the useful length of station tracks on the average weight of freight train trains depending on the structure of freight flows of the main railway line; actual value of average weight of freight trains is set taking into account different weight standards. The value of the weight norm is determined, at which, in case of restrictions on the useful length of the station tracks, the use of power of train locomotives deteriorates. Power, and accordingly, the type of train locomotives varies depending on the average weight of the train.
   The presence of cargo flows not only from heavy, but also from light cargoes creates the possibility of driving freight trains with low-power locomotives. For driving heavy trains, more powerful two and three-section locomotives, multiple traction, can be used.
   The increase in the number of low-weight trains allows, by reducing the time spent on accumulation, as well as downtime of ready-to-leave trains waiting for train locomotives during a period of decline in traffic, to reduce the fleet of cars and their downtime at sorting stations. This will ensure stability in the operation of junction points by ensuring more uniform operation of main railway lines.

In large cities and agglomerations, the transition from personal to public transport for work and household trips is an important task. Thus, a huge number of private cars creates a large and ever-increasing load on the city's road network, negatively affects the environment, including due to exhaust gas emissions, noise pollution, as well as related harmful processes during vehicle maintenance. To provide a worthy alternative to personal transport, it is required to monitor the current congestion of public city routes and, on the basis of this, form reserves of their capacity. This paper discusses a method for determining passenger flows on urban routes by geolocation of mobile devices in the nearest passenger generating points with reference to the time of day and day of the week. Such an approach can be promising not only for determining the total volume of traffic performed by the rolling stock of urban transport, but also for determining the occupancy of the vehicle, and as a result, for calculating the average passenger travel distance. In this regard, a second method is proposed, consisting of a number of formulas have been proposed that allow determining the coefficient of uniqueness of passengers on a route, taking into account the time of day and the seasonality of demand for urban transportation, followed by calculating the travel distance of a unique passenger, which, ultimately, allows a more detailed representation of the population's needs for transportation, as well as weak places in the urban transport infrastructure. The proposed methods are universal and can be used both for buses and trolleybuses, as well as for trams and even the metro. Also, the first method can be used as a tool for research and management of human flows in the urban environment (pedestrian flows).

The development of transport infrastructure is a priority task for our country with its vast and not fully developed territories. Transport construction requires the use of advanced technologies and the most modern and high-performance construction equipment. The article substantiates the relevance and importance of the process of compaction of road materials in the construction of earth embankments of highways. It is the subgrade that is the supporting engineering structure for the expensive upper layers of the road base and pavement. If the subgrade soils are poorly compacted, this will lead not only to the destruction of the earth embankment itself, but also to the destruction of the upper technological layers located on it, and these are unacceptable losses. Self-propelled road rollers are the main machines that compact the technological layers of the road, ensuring their strength and durability. Various designs and types of road rollers have appeared due to the variety of compacted materials and their properties. To ensure an efficient compaction process, it is necessary to correctly select not only the type of compacting machine, but also its operating modes. A new working body of a road roller capable of regulating contact pressures in an extended range is considered. An experimental sample and a calculation scheme for determining the main parameters are presented. The article provides a developed methodology for substantiating the parameters of a road roller with a new working body for the construction of transport infrastructure. The use of a new design roller and properly selected parameters of its operation will increase the efficiency of construction and reduce the cost of the technological operation of compacting the subgrade layers.

   An important design feature of prefabricated monolithic structures is that they consist of prefabricated and monolithic parts, represented in turn by concrete of different ages, as well as, sometimes, of different types and classes. In the end, prefabricated monolithic structures consist of concretes with different strength, deformation and other physical and mechanical properties. In addition, it is also possible to involve precast and monolithic concrete in the deformation process at different times and simultaneously. Thus, it becomes obvious that both the nature of the formation of the stress-strain state and the calculations of prefabricated monolithic structures for the first and second groups of limit states are much more complex than for reinforced concrete structures consisting of concretes of the same type. The design features listed above should be reflected in the regulatory methods for the calculation of prefabricated monolithic structures.
   Within the framework of this article, certain refinements are proposed in relation to existing methods for calculating prefabricated monolithic structures for the second group of limit states. These refinements were determined on the basis of studying the structural features inherent in prefabricated-monolithic bent elements and determining the features of the formation of their stress-strain state. In addition, normative methods for calculating prefabricated monolithic structures for the second group of limit states, as well as other methods recommended by various scientists and engineers of the construction field, were considered. The methodology presented by the authors for calculating prefabricated monolithic structures for the second group of limit states allows us to take into account the features of such structures, including the difference in the deformation and strength properties of these concretes.
   Satisfactory convergence was obtained by comparing the results of theoretical calculations with the data obtained during experimental studies.

Soil is an important component in the system of biological protection of the road structure sloping part. The adaptive capacity of plants and the biological activity of soils based on peat, sand and sewage sludge were evaluated by biotesting using agricultural plants. It has been established that the use of sewage sludge does not lead to a significant increase in the accumulation of nitrates and heavy metals in the green mass of agricultural plants. Therefore, such sediments can be used as soil-improving additives in anthropogenically disturbed areas, mixed with fillers that create porosity and ensure water movement while minimizing leaching of ingredients. A variant of the technological scheme for preparing soil in the field is proposed, which provides for intensive mixing of sewage sludge with peat and sand, thermal shearing effect on the mixture, transportation, unloading and temporary storage for the purpose of the resulting soil phytoredimentation. The use of the newly developed technology will make it possible to obtain artificial soils that meet sanitary standards for pathogenic microorganisms, the content of heavy metal salts and organic ecotoxicants, and also meet the requirements for soils for the biological protection of railway and highway slopes.

   Wind loads lead to bridge oscillations. To verify aeroelastic stability of superstructures physical aerodynamic investigations are performed with vehicles taken into consideration. Usually oscillation amplitudes in this configuration are much bigger than without vehicles. At the same time, stiffness and damping of the vehicles are not modeled as that could decrease oscillation amplitudes.
   The main goal of this work is to determine vehicle influence on bridge superstructure damping. To solve the system of equations of motion from which vertical oscillations of vehicle – structure system were determined implicit Newmark method was implemented. Vehicle – structure system damping was assessed by logarithmic oscillations decrement, obtained from the results of free decay and forced resonance vibrations.
   Calculations were performed with different number of traffic lanes used by vehicles. Furthermore, suspension stiffness and damping also varied. As a result, it was obtained that for suspension with good damping characteristics vehicle – structure damping system was several times bigger than for superstructure without vehicles. With a satisfactory condition of the suspensions, the influence of vehicles can be estimated at 20 %.
   The obtained results can allow increasing the decrement of superstructure model in physical aerodynamic investigations with consideration of vehicles. However, it is necessary to carry out some research on determination of most frequently used vehicles’ suspensions.

The aim of the work is to evaluate the actual errors in the hydraulic calculation of the characteristics of drainage pipes with internal deposits and compare them with the characteristics of new pipes. As a research method, a quantitative method for evaluating (comparing) the results of calculating the values of the hydraulic characteristics of new pipes and pipes with different thicknesses of the sediment layer in their flume part was used. A specific example was used to compare the results of new pipes hydraulic calculation and pipes with different deposit thicknesses. Graphs of the pipes design characteristics dependence on the actual thickness of the internal deposits layer are given. Taking into account the relative error in calculating the values of the hydraulic characteristics of pipes, graphs of the actual values hydraulic characteristics networks pipes dependence for the conditions of the given problem are given. It is proposed to quantify the values of the hydraulic characteristics of drainage pipes, taking into account the actual thickness of the sediment layer in their flume. A device for measuring the actual thickness of the sediment layer is recommended. It is proposed to develop a special reference manual for hydraulic calculation of pipes with a specific thickness of the deposits layer in their flume, as well as a method for substantiating the need for hydrodynamic cleaning of gravity sewage networks with deposits in their flume.

   The problem of fatigue cracking in the welded joints of metal bridge spans is one of the most actual nowadays. Today about 20 % of bridge spans with cracks, including non-localized ones, are in operation on the Russian Railways network. At the same time the number of such defects continues to grow and has considerably increased during the last decade. It is necessary to note, that there are rather many researches of fatigue life of welded elements, before crack formation, but there are practically no researches of growth rate and dynamics of their development. Besides, the boundary (critical) sizes of cracks, essentially influencing a condition of constructions, confirmed by calculations are absent.
   This paper presents the results of experimental laboratory studies of fatigue crack growth rate similar to T-9 cracks (according to the accepted classification) arising in the nodes of welded metal bridge spans. Laboratory tests were carried out by a patented technique with corresponding control of crack formation. One of the most important components of determining the crack growth rate was to determine the crack length at which its uncontrolled growth occurs. This is necessary to predict the crack growth and to take timely measures to eliminate or inhibit it.
   According to the results of the studies, the dependences of the growth rate on various parameters have been obtained. A new parameter of crack growth – acceleration – an increase in the crack growth rate over a certain period of time, which most clearly expresses the beginning of its uncontrolled growth, has been introduced. Stable crack growth is observed during 1.6 million load cycles with a gradual increase in the growth rate, with crack length during this period varying from 30 to 160 mm. At a crack length of 160 mm and a growth rate of 1.3·10–4 mm/cycle a significant increase in the growth rate begins, which allows us to accept these parameters as critical, at which uncontrolled crack growth begins.

  To exclude transport structures roadbed frost heave deformations operated in unfavorable climatic and soil-hydrological conditions, methods are often used to transform the clay soils properties of the working layer (core). One of the ways to transform the clay soils properties is silicification - impregnation of soils with a solution of sodium silicate, the so-called liquid glass, through injectors of a special design. At the same time, the question of the change patterns in the coefficients of initial soils frost heaving during silicification remains unsolved. In this regard, the purpose of the research is to determine the dependence of the change in the coefficients of frost heaving of silicified soil on the concentration of sodium silicate solution and the soil plasticity number.
   As part of the research, a laboratory experiment was carried out. The GT 1.1.12 automated device was used as the main laboratory setup for the implementation of the experiment. Based on the results of the research, using statistical data processing methods, the functional dependences of the change in the frost heaving coefficients on the concentration of the solution and soil plasticity number during the silicification of clay soils used for backfilling the subgrade of transport structures were established.
   The obtained results of the research allow, with a known type of exploited subgrade soil, to assign the optimal concentration of sodium silicate solution and calculate other parameters of full or partial silicification, for example, when creating a capillary barrier, silicification of the working layer or the active zone of the structure.