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Human activities are related to obtain economic, technical, social and environmental benefits. The road construction process participants and road users have direct or indirect benefits from elaboration of new infrastructure. The number of the benefits received by individual entities is publicly discussed by politicians, lobbyists, experts and other decision-makers without having quantitative estimates of benefits, i.e., often relying on intuition or considering theoretical reasoning. The paper suggests a system of 19 benefit entities (criteria) assigned the ranks given by experts. The study involved three categories of experts, including 35 road engineers, 36 transport engineers and 61 road users. The values of the concordance coefficients obtained as a result of the conducted research were found significantly higher than critical values and showed that the opinions of the experts in each category were consistent (not contradictory). This made it possible to consider the average of the opinions of the expert group as a reliable result of solving the problem. Rank averages were replaced by the normalized weights of criteria using Average Rank Transformation into Weight-Linear (ARTIW-L) and – Nonlinear (ARTIW-N) methods. The global averages of criterion weights were used employing the Inverse Hierarchy for Assessment Main Criteria Importance (IHAMCI) method thus calculating the normalized weights of the road-related classified entities (three main criteria). The findings prove that road users benefit the most (weight 0.3485), the road construction contractor (weight 0.3325) is in the next position and the road owner (investor) takes the weight equal to 0.3190. The generated research data can be used for justifying the rationality of road investment.

The article examines the increasingly prevalent and popular issue of electric scooters, classified as micromobility, participating in traffic in various cities worldwide and in Lithuania. The aim of the research is to present and analyze the experiences of Lithuania and foreign countries in developing infrastructure and legal frameworks for safer electric scooter traffic. It analyzes their benefits, legal regulations governing their use, and the adaptation of infrastructure for electric scooter traffic. Statistics from four years of traffic accidents involving scooters are provided, their primary locations and causes are analyzed, and conclusions and recommendations for improving electric scooter traffic safety are presented. The analysis shows that in Lithuania, the number of traffic accidents with scooters and the number of casualties in them increase annually, while the legal regulation and adaptation of infrastructure for electric scooter traffic vary among different countries. Article in Lithuanian. Elektrinių paspirtukų saugaus eismo problemos Lietuvoje Santrauka Straipsnyje nagrinėjama vis labiau įvairiuose pasaulio ir Lietuvos miestuose plintančios ir populiarios mikromobilumui priskiriamos transporto priemonės – elektrinių paspirtukų dalyvavimo eisme problema. Tyrimų tikslas yra pateikti ir išanalizuoti Lietuvos bei užsienio šalių patirtį, kuriant infrastruktūrą bei teisinę bazę saugesniam elektrinių paspirtukų eismui. Analizuojama jų nauda, teisinis naudojimo reglamentavimas, infrastruktūros pritaikymas elektrinių paspirtukų eismui. Pateikiama ketverių metų eismo įvykių su paspirtukais statistika, analizuojamos jų pagrindinės vietos bei priežastys, pateikiamos išvados ir rekomendacijos elektrinių paspirtukų eismo saugumui gerinti. Atlikta analizė rodo, kad Lietuvoje eismo įvykių su paspirtukais ir nukentėjusiųjų juose skaičius kasmet didėja, teisinis reglamentavimas bei infrastruktūros pritaikymas elektrinių paspirtukų eismui atskirose šalyse yra skirtingas. Reikšminiai žodžiai: elektrinis paspirtukas, mikromobilumas, eismo saugumas, infrastruktūra eismo dalyviams.

The speeding is a major road safety problem on the roads of Lithuania and many other countries. To reduce and control the speed of vehicles, engineering measures are installed on the roads of Lithuania and other countries – intelligent instantaneous and average speed enforcement systems, as well as many other engineering and structural speed reduction measures. The article presents good practices in the use of average speed enforcement systems, assessment of their effect on road safety. The article analyses the assessment results of the effect of the average speed enforcement systems installed on 25 sections of roads in Lithuania that have been operating for four years. Calculations of the effect factor of the installed average speed enforcement systems on road safety were performed using the before-and-after (B&A) method with a comparison group. Studies on the effect of application of speed control systems provide conditions for evaluating road safety, i.e., changes in road accidents linked to the effectiveness of implemented measures. The conclusions of the conducted study presented the calculations of the efficiency coefficients of the average speed enforcement systems on Lithuanian main and national roads. The analysis of the results of the conducted study allows stating that the installed average speed enforcement systems on 25 sections of Lithuanian roads increase overall road safety by 47%, reduce the number of collisions with animals by 80%, and the number of collisions with vehicles by 35%, as well as the number of other road accidents by 56%.

The article deals with the problems of the use of self-driving vehicles (SDV) on public the adaptation of road infrastructures well as with, the necessity and objectives of assessment, and the experience of foreign countries in this field. The main factors influencing for SDV were analyzed. An evaluation model of infrastructure adaptation for SDV has been developed, allowing rational planning and selection of the most appropriate selfdriving public transport routes. In order to efficiently integrate SDV into transport systems, it is recommended to evaluate the potential route alternatives using the SAW method and also to use the efficiency indicators proposed in the thesis and their significance. After analyzing the theoretical and practical aspects of road infrastructure adaptation for SDV conclusions and suggestions are given. Article in Lithuanian. Kelių infrastruktūros pritaikymo savivaldėms transporto priemonėms vertinimas Santrauka Straipsnyje nagrinėjamos savivaldžių transporto priemonių (STP) naudojimo viešuosiuose keliuose ir kelių infrastruktūros pritaikymo jų eismui problemos, vertinimo būtinumas ir tikslai, užsienio šalių patirtis šioje srityje. Išnagrinėti pagrindiniai faktoriai, turintys įtaką savivaldžių automobilių eismui. Sukurtas STP infrastruktūros pritaikymo vertinimo modelis, leidžiantis racionaliai planuoti bei parinkti tinkamiausius savivaldžių viešojo transporto priemonių maršrutus. Siekiant efektyviai integruoti STP į susisiekimo sistemas, rekomenduojama potencialias maršrutų alternatyvas vertinti taikant SAW metodą ir taip pat naudoti darbe pasiūlytus efektyvumo rodiklius bei jų reikšmingumus. Išnagrinėjus teorinius ir praktinius kelių infrastruktūros pritaikymo STP vertinimo aspektus, pateikiamos išvados ir siūlymai. Reikšminiai žodžiai: savivaldis automobilis, savivaldė transporto priemonė, miestų infrastruktūra, rodikliai, keliai, daugiakriteris vertinimas, SAW.

For the use of the national highway network of Lithuania, freight vehicles pay a fee of a fixed amount using the system of purchasing electronic vignettes (hereinafter referred to as e. vignettes). The tax is paid for a certain period (day, week, month, or year) regardless of the distance traveled by vehicles. Such a taxation model does not value the “polluter pays” principle enshrined in EU legislation and does not allow covering the damage caused by freight vehicles to the road infrastructure. Road maintenance and development program financing law no. VIII-2032 by the law on the amendment of articles 2, 6, 9 and appendices 2, 5, VĮ Lithuanian Road Directorate until 2023 must develop and implement an electronic road toll system that should replace the currently used e. vignettes. The article presents the currently tolled road network of Lithuania, the financial impact on the companies providing transportation services after the introduction of the electronic road toll system. The road toll systems operating in European countries and Lithuania and their operating technologies, marginal tariffs are analyzed, and a methodology is proposed, based on which it would be possible to fill in the list of currently tolled roads. A company providing cargo transportation services has been selected, and it has been determined how the amount of paid taxes will change after the implementation of the electronic road toll system on Lithuanian roads. It has been determined that after the introduction of EKRS for companies providing transportation services that carry out long-distance transport in Lithuania, the amount of taxes paid for using state roads will increase significantly. Article in Lithuanian. Elektroninė kelių rinkliavos sistema ir jos diegimas Lietuvos automobilių keliuose Santrauka Už naudojimąsi Lietuvos valstybinės reikšmės magistralinių kelių tinklu krovininės transporto priemonės moka nustatyto dydžio mokestį naudodamos elektroninių vinječių (toliau – e. vinječių) įsigijimo sistemą. Mokestis yra mokamas už tam tikrą laikotarpį (parą, savaitę, mėnesį ar metus) neatsižvelgiant į transporto priemonių nuvažiuotą atstumą. Toks apmokestinimo modelis neįvertina ES teisės aktuose įtvirtinto principo „teršėjas moka“ ir neleidžia padengti krovininių transporto priemonių padarytos žalos kelių infrastruktūrai. Kelių priežiūros ir plėtros programos finansavimo įstatymo Nr. VIII-2032 2, 6, 9 straipsnių ir 2, 5 priedų pakeitimo įstatymu VĮ Lietuvos automobilių kelių direkcija iki 2023 m. turi sukurti ir įdiegti elektroninę kelių rinkliavos sistemą, kuri turėtų pakeisti šiuo metu naudojamas e. vinjetes. Straipsnyje pateikiamas dabar apmokestinamas Lietuvos automobilių kelių tinklas, finansinis poveikis transportavimo paslaugas teikiančioms įmonėms, įdiegus elektroninę kelių rinkliavos sistemą. Analizuojamos Europos šalyse ir Lietuvoje veikiančios kelių rinkliavos sistemos ir jų veikimo technologijos, ribiniai tarifai, pasiūlyta metodika, kurios pagrindu būtų galima pildyti dabar apmokestinamų kelių sąrašą. Pasirinkta krovinių pervežimo paslaugas teikianti įmonė ir nustatyta, kaip pasikeis sumokamų mokesčių dydis įgyvendinus elektroninę kelių rinkliavos sistemą Lietuvos automobilių keliuose. Nustatyta, jog įdiegus EKRS transportavimo paslaugas teikiančioms įmonėms, pervežimus atliekančioms dideliais atstumas Lietuvoje, sumokamų mokesčių dydis už naudojimąsi valstybinės reikšmės keliais itin išaugs. Reikšminiai žodžiai: e. vinjetė, elektroninė kelių rinkliava, kelių naudotojo mokestis, Kelių priežiūros ir plėtros programa.

Properly designed and maintained asphalt pavements operate for ten to twenty-five years and have to be rehabilitated after that period. Cold in-place recycling has priority over all other rehabilitation methods since it is done without preheating and transportation of reclaimed asphalt pavement. Multiple researches on the performance of cold recycled mixtures have been done; however, it is unclear how the entire pavement structure (cold recycled asphalt pavement overlaid with asphalt mixture) performs depending on binding agents. The main objective of this research was to evaluate the performance of cold in-place recycled asphalt pavements considering binding agents (foamed bitumen in combination with cement or only cement) and figure out which binder leads to the best pavement performance. Three road sections rehabilitated in 2000, 2003, and 2005 were analysed. The performance of the entire pavement structure was evaluated in terms of the International Roughness Index, rut depth, and pavement surface distress in 2013 and 2017.

Planned special events (PSEs) attract more people than usual to specific areas, which leads to increased traffic flows and congestions on the roads. Roadwork zones are among the most vulnerable areas on the roads, where increased traffic can lead to congestion. In roadwork zones, the vehicle flow capacity is already lower than in the conventional situations without roadworks, but at the time of PSEs, these zones become difficult to pass if no attention is paid to the change of the traffic management scheme. This kind of events poses many threats for road authorities, thus, new traffic management systems should be considered. This paper analyzes 2 PSEs and one national celebration in Lithuania and a significant impact they have on the regular traffic flow. PSEs are taken into consideration as they attract traffic to a known place; however, national celebrations distort traffic along all roads and it is not known exactly, which roads will be congested the most. Since roadwork zones cause congestion problems even in conventional situations, this paper presents traffic capacity calculations at these road stretches during PSEs and considers how they change depending on the traffic management scheme.

Average speed enforcement systems have been used on the roads of foreign countries for many years already, and give a positive effect on reducing accident number. The article presents good practices in the use of average speed enforcement systems in various countries and their impact on improving traffic safety. The article analyses the experience of system installation on the roads of Lithuania and the first results. The article also proposes methodologies for the selection of road sections to be enforced, the equipment used, and distribution of road sections in the road network of Lithuania. A detail analysis is given of the effect of average speed enforcement systems after their installation in three different periods on 25 road sections. The analysed data is differentiated between main and national roads. Conclusions and recommendations are given at the end of the paper for a future development of average speed enforcement systems.

However, for several decades, Europe has been witnessing demographic ageing. As a result of these changes, a more significant number of elderly road users will be involved in future traffic, and therefore safe mobility management of the older will become an increasingly important issue. Various physical, sensory, and cognitive constraints affecting elderly road users lead to a rise in the likelihood of an accident, which, due to the increased physical vulnerability, cause more serious consequences of road accidents. The findings reported by the authors of an in-depth analysis of accidents for four years have demonstrated that the risk of road fatalities for elderly road users is by one fifth more significant than the average of all age groups, and the pedestrian plays the most critical role in road traffic. To adequately compensate for the observed age-related physiological changes, the authors discuss actions and road safety measures to ensure appropriate conditions for older pedestrians on the streets.

Mechanical properties and slab dimensions of concrete are the major parameters based on which the performance of concrete pavement structures is predicted. Precast concrete pavement, as one of the most common modular pavement type, is the advanced next-generation technology characterised as high quality, durable, quickly built and easily maintained. The service conditions of precast concrete pavement (traffic loading and environmental effects) are similar to the conventional cast-in-place jointed plain concrete pavement. Thus, the precast concrete pavement structural design is similar to that of jointed plain concrete pavement. There are several concepts for the design of concrete pavement structure. However, they are based on different distress evaluation and critical stresses estimation methods assuming the slab dimensions that for jointed plain concrete pavement are within the wide joint spacing range from 3.5−6.0 m. The objective of this paper is to analytically evaluate the effect of concrete mixture mechanical properties on the thickness and dimensions of precast concrete pavement slab. Also, define the minimal thickness of precast concrete slab dependent on slab dimensions and concrete mixture mechanical properties elastic modulus and tensile splitting strength. The analysis is based on bearing capacity, performance and fatigue boundary conditions as reported by semi-probabilistic pavement design method Richtlinien für die rechnerische Dimensionierung von Betondecken im Oberbau von Verkehrsflächen RDO Beton 09. Considering that, concrete mixture has significant effects on pavement performance; the composition of concrete was also discussed in this paper. The optimal slab dimensions, concrete layer thickness, and base layer type is suggested in this paper. The outcomes of this analysis apply to the production of precast concrete pavement slabs.

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.

In the context of increasing traffic demands and emerging mobility trends road infrastructure has to shift towards the fifth generation of roads, which according to Forever Open Road (FOR) vision are envisioned as adaptable to traffic volumes, resilient to changing weather conditions, quickly built, effectively maintained, suitable for retrofitting, self-monitoring, self-repairing and recyclable. Concrete modular pavements can be defined as an example of such type of road infrastructure. Functional needs are mainly associated with implementation area/location, traffic and mobility demands, environmental constraints and etc. This also has a significant impact on the selection of Precast Concrete Pavements (PCP) texture formation method and materials. Concrete pavement surface texture affects both safety and tyre/road noise characteristics. Exposed Aggregate Concrete (EAC) and porous concrete are the most suitable noise reducing solutions for highways and streets wearing layer even in severe traffic and climate conditions. According to the literature analysis, the algorithm of highways and streets low noise concrete design was created. It is recommended to use the highest quality aggregates with maximum size up to 8 mm, gap-graded gradation, higher amount of cement and lower water/cement ratio. The most important characteristics of EAC are Mean Profile Depth (MPD), Mean Texture Depth (MTD) and profile count, while the most important characteristics of porous concrete are compressive strength, outflow and air void content.

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.

As the railway lifespan is the main criterion for selection of the aggregate for ballast and for planning the maintenance of the railroad, it is important to define the relationship between the particle load resistant characteristics and a lifetime of ballast in structure. Assessment of the quality of the ballast aggregate particles under dynamic and static loading reflect both, the toughness and hardness, and these are identified with the Los Angeles Abrasion and Micro-Deval Abrasion values. The model formerly developed by Canadian Pacific Railroads was adapted to predict possible loads expressed in cumulated tonnes. Different ballast aggregate mixtures were tested in the laboratory including dolomite and granite. Calculated potential gross tonnage (expressed in Million Gross Tonnes) of the railway per lifetime for each different aggregate type presented. The outcome of this research is established classification system of railway ballast aggregate and defined Los Angeles Abrasion and Micro-Deval Abrasion values of aggregate dependently on required lifetime.

Even though every layer of pavement structure is important and affects pavement performance, the asphalt layers visco-elasticity plays significant role. Bitumen properties, as well as asphalt mixture properties, vary depending on temperature and loading conditions. These variations influence entire pavement bearing capacity and has to be evaluated in pavement design. The main challenge is material behaviour description through simple models to incorporate them to pavement design. Generally, pavements are designed using Multilayer Elastic Theory assuming that all materials are elastic, isotropic, and homogenous. This paper presents analysis of two pavement structures response calculated according to three pavement design approaches. The dynamic modulus and phase angle of asphalt mixtures was estimated using Hirsch model after binder complex shear modulus tests. The visco-elastic behaviour was described with rheological Huet-Sayegh model and pavement responses estimation was done using MnLayer and ViscoRoute2 software. The analysis reviled static and dynamic load influence on pavement structure based on elastic and visco-elastic properties of asphalt layers. This allowed optimisation of layer thicknesses and determination of more cost beneficial pavement structure with appropriate performance.

Atmospheric pollution began to increase in the beginning of 19th century, when the global economy and industrial development started the signal grow. The current problem of global warming is partly related with emission of carbon dioxide (CO2) to environment, which one of the sources are industrial production companies. Warm asphalt mix is usually used in the practice of Lithuania and the world for equipment of road paving. These mixes are produced in specialized asphalt mixers where stone dosing, drying and its mixing with bituminous binders are performed. The temperature of produced hot asphalt mix in mixer reach 150–180 °C and 120–160 °C of mixture laying on the road. Various pollutants, carbon dioxide, formaldehydes, and other are spread to the environment. The carried out researches in Lithuania and the world have showed that while using special additives it is possible to reduce the temperatures of warm asphalt production and laying on the road. Such reduction of temperature helps not to worsen the quality of asphalt layer, to lower the emission of pollutants to environment, to improve the conditions of road workers and to economically use the gas for production of asphalt mixes. Production technologies of different asphalt mixes, their advantages and disadvantages, and results of laboratory tests are analyzed in this article. Equipment samples of experimental road sections, using the warm mixing asphalt mixtures are given. Santrauka 19 amžiaus pradžioje, ėmus sparčiai augti pasaulinei ekonomikai ir vystytis pramonei, pradėjo didėti ir atmosferos užterštumas. Dabartinė globalinė pasaulinio atšilimo problema iš dalies siejama su anglies dioksido (CO2) išmetimu į aplinką, kurio vienas iš šaltinių yra pramoninės gamybos įmonės. Automobilių kelių dangoms įrengti Lietuvos ir pasaulinėje praktikoje dažniausiai naudojami karšto asfalto mišiniai. Šie mišiniai yra gaminami specialiuose asfalto maišytuvuose, kuriuose akmens medžiagos dozuojamos, džiovinamos, maišomos su bituminiais rišikliais. Gaminamo karšto asfalto mišinio temperatūra maišytuve siekia 150–180 oC, o kelyje klojamo – 120–160 oC. Šių procesų metu į aplinką paskleidžiama įvairių teršalų: anglies dioksido, formaldehidų ir kt. Pasaulyje ir Lietuvoje atlikti moksliniai tyrimai parodė, kad naudojant specialius priedus galima sumažinti karštų asfalto mišinių gamybos bei klojimo kelyje temperatūrą. Toks temperatūros sumažinimas leidžia nepabloginti asfalto dangų kokybės, sumažinti teršalų išmetimą į aplinką, pagerinti kelyje dirbančių darbuotojų darbo sąlygas, ekonomiškiau naudoti asfalto mišinių gamybai reikalingas dujas. Šiame straipsnyje analizuojamos skirtingų asfalto mišinių gamybos technologijos, jų privalumai ir trūkumai, laboratorinių bandymų rezultatai. Pateikiami eksperimentinių kelių ruožų įrengimo pavyzdžiai, naudojant šiltojo maišymo asfalto mišinius. Reikšminiai žodžiai: šiltojo maišymo asfaltas, ceolitas, CO2 sumažėjimas.

Road transport is by far the most convenient way of transportation these days, offering the highest mobility and flexibility. While road transport is gaining popularity, the increased amount of traffic requires proper improvements and maintenance of the road network. The increasing usage of roads requires highest levels of maintenance of the road network. To ensure that, new methods with the ability of rapid, non-destructive monitoring and testing of the construction properties are on demand. Review and analysis of flexible road pavement testing means and methods are presented in this paper to introduce the problem and current technology. Complexity of these methods is pointed out. New approach to pavement testing using vibro-excitation and logarithmic decrement analysis of extinguishing free oscillations is proposed and its advantages are shown with application possibilities in a new advanced non-destructive pavement structure research device.

This summary of the author’s PhD thesis defended on 20 December 2012 at the Vilnius Gediminas Technical University. The thesis is written in Lithuanian and is available from the author upon request. Chapter 1 describes the analysis of road infrastructure safety management procedures and their implementation. Chapter 2 gives the overview of accident prediction models and the principles of their development. Chapter 3 presents the designed accident prediction algorithm for the roads of national significance of Lithuania, the developed mathematical accident prediction models for homogenous groups of roads and junctions, the implemented network safety ranking and the determined road sections with a potentially high accident concentration. Chapter 4 describes the testing and analysis of software intended for the implementation of accident prediction algorithm.

The strength and durability of road pavement structures are directly influenced by the way in which asphalt layers are bonded. An insufficient bond between pavement layers leads to wearing, tearing, pavement deterioration, and cracking, and the pavement life span is reduced. The quality of bond between pavement layers was determined by direct shear test, using the so called Leutner method, without normal stress in specimen. Test samples were taken at various locations along the Lithuanian road network, from pavements characterized by standard asphalt structure, and reinforced asphalt structure in which geosynthetic materials are used in interlayers.

In 2012, the Lithuanian Road Administration initiated a three-year research project ‘The study of effective winter road maintenance of national significance roads in Lithuania’. The main purpose of this research was to optimize road maintenance in winter and to determine the most effective means of combating slippery conditions. The research project was carried out by two institutions: the Road Research Institute of the Faculty of Environmental Engineering of Vilnius Gediminas Technical University and JSC ‘Problematika’. JSC ‘Problematika’ conducted exploratory experiments, which were divided into two phases. In the first phase of the experiment, five different snow melting materials (Slipperiness Reducing Materials – SRMs) were investigated in the laboratory. Different test methods were used in this investigation. In the second phase of the experiment, three SRMs with different properties were selected, and experimental road sections were set up to determine the road slipperiness and the change in coating layer thickness over time concerning different environmental conditions, as well as different snow and ice layer thicknesses. An optical remote sensor of Road Condition Monitor (RCM 411) was used for friction measurements on the roads. This report covers the laboratory test results of five different SRMs, road slipperiness measurement results using three selected SRMs and their analysis, comparison of the performance efficiency of the most widely used SRMs in Lithuania and the tested SRMs under different environmental conditions.

The roads as main national assets maintenance costs increase dramatically but budgets stays as it is or even decrease over the years. However, at the same time, it is required to maintain road pavements condition at high level. These trends make asset owners and administrators to search for new ways and methods for more efficient roads maintenance management. As the new road is build or old one reconstructed performance indicators should be identified for whole life cycle as it is defined by design. Pavement condition evaluation by indicating present performance indicators level should be done timely and accurate at road level and whole network level. Ongoing support of pavement condition under network level, with a long-term strategy, allows to prolong the life of the pavement, improve traffic safety and meet public expectations. The comprehensive analysis of road maintenance and management systems recommendations for their improvement and application are presented in the article.

The Directive 2008/96/EC of the European Parliament and of the Council of 19 November 2008 on Road Infrastructure Safety Management requires that the Member States shall establish and implement the network safety ranking. Safety performance of existing roads should be increased by targeting investments to the highest accident concentration sections and (or) to the road sections or crossings with the highest accident reduction potential. Road network safety management is applied within the road network in operation covering the selection of traffic safety improvement measures in optimal locations, evaluation of the safety effects and implementing the measures. The article describes the method for selecting and prioritising road sections which have higher than the average accident saving potential in each road category. When selecting road sections for treatment, a potential reduction of accident costs shall be taken into consideration. Road sections in each category are studied and classified by the factors related to road safety, such as the number of accidents, traffic flow and road characteristics. The article describes how the procedure of the road network safety ranking and the ranking of high accident concentration sections is implemented in Lithuania and propose further steps.

Due to destructive factors (traffic loads, climatic and weather conditions, improper exploitation materials), bitumen properties irreversibly change in unservicable asphalt concrete. Due to irreversible processes of oxidation the aged bitumen stiffens, its physiochemical properties, ductility, adhesion and cohesion as well as sectional composition (relative amounts of asphaltenes, oils and resins) change. Bitumen in the reclaimed asphalt pavement (RAP) may be restored to properties approximate to those of the virgin bitumen by adding the following rejuvenators: softening or rejuvenating agents as well as soft bitumen. The article presents the experimental data on RAP obtained from laboratory tests conducted with Marshall specimens without additives when RAP was supplemented by different types of virgin road bitumen, the paving grade of which was 50/70, 70/100, 100/150, 160/220, respectively. The content of newly added binder of all types to RAP was 0.5%, 1.0%, 1.5%, 2.0%, and 50/70 in addition and 4.0% and 6.0% of RAP mass. The total bitumen content increased by the same percentage amount in the reclaimed asphalt, which was not always optimal. Marshall specimens were formed with these bitumen contents, the tests of which enabled to identify stability (S), flow (F), Marshall quotient (S/F), air voids content (Vm), bulk density (SDD – ρb SD) of asphalt concrete samples and the maximum density of asphalt. Having extracted all RAP and reclaimed asphalt samples according to the differential method, the factual content of soluble binder in them and its penetration, softening point, Fraass breaking point, ductility and penetration index Ip were calculated. The dependences of the reclaimed asphalt physical and mechanical parameters on the virgin rejuvenating bitumen grade and its added percentage amount were obtained. Data analysis and their generalization was conducted.

Analysis of the literature has shown that two main factors, which should be taking into consideration in designing of continuous bridges, are the influence of cracking on serviceability of the structures and inelastic behaviour of structural elements. Crack control is often the governing design criterion for the choice of the amount of longitudinal pre-stressing of reinforced concrete bridges as well as for the construction sequence of composite bridges. Present paper investigates cracking behaviour of reinforced concrete decks of continuous bridges over intermediate supports. It should be noted that this section behaves almost as pure tension ties. The paper presents results of complex investigation which has included experimental and numerical analyses of deformations and cracking resistance of reinforced concrete tensile members and a deck slab. Different techniques on crack controlling were analysed. Analysis was showed that the techniques worth predicting deformational behaviour of reinforced concrete members as well as assuring the cracking control in the bridge deck.

The falling weight deflectometer (FWD) is the device most commonly used for the measurement of strength of road pavement structure. Using this device the impact of the wheel of heavy vehicle to the pavement is imitated for the assessment of pavement strength. The stiffness of asphalt pavement layers, as well as E0 modulus values, measured using the FWD, strongly depend on the pavement temperature. When we use deflectometer for measuring asphalt pavement strength at different environmental conditions and in different season the values of E0 modulus should be reduced to the assumed standard temperature. During this research at the experimental asphalt pavement structure the temperature correction factor was revised. The use of this factor enables to reduce the values of the stiffness of asphalt pavement layers measured by the falling weight deflectometer to the standard temperature of +20 °C. In this way the influence of the temperature of asphalt pavement layers upon asphalt stiffness and E0 modulus could be evaluated.

Production of hot mix asphalt (HMA) requires a lot of consumption of energy, exhaustion of CO2 and other environment unfriendly materials. The fumes of HMA are injurious for roadmen and asphalt plant workers. The use of warm mix asphalt (WMA) allows reducing the HMA production temperatures at which the material is mixed and laid on the road. WMA helps to reduce the working temperature of asphalt up to 30 °C. This article presents the overview of different technologies of WMA production, advantages and disadvantages of these technologies. The laboratory research includes research of physical and mechanical properties of WMA produced with different technologies and different amount of additives for temperature lowering. Two different kinds of asphalt where tested in the laboratory. The chemical additives and chemical and natural zeolite were used for WMA production in the laboratory.

The rapid growth of heavy traffic, the increase in the standard axle load make scientists to look forward for new durable road constructing materials and their mixes. The continuously increasing need for strengthening the road pavement structures induces to use new road reconstruction technologies, to search for new methods in constructing pavement structural layers and investigate pavement structures under real conditions. The article presents construction of experimental pavement structures for the first time in the road history of Lithuania. The article also describes the installation process of stress and strain transducers in different layers of experimental pavement structures and initial results of stress and strain measurements. These measurements will be carried out each time after passed 20 000 ESAL’s calculated to 100 kN.

The paper deals with the performance of geotextiles separation function in road pavement structure and geotextile damage from transport loads. The experimental research consists of installation of two different types geotextiles on the bottom of the sub-base (gravel-granite mix, granite and dolomite) of road pavement structure with and without asphalt pavement. Throughout research evaluation of geotextiles damage and separation function performance depends on impact of different amount of vehicle loads has to be done. On stage I performance of separation function and geotextiles damage evaluated after 34 000 equivalent single axle loads (ESALs).

Practically all the road-related questions are solved with the consideration of climatic factors. Besides, the meteorological characteristics of the region, where the road objects are located, are taken into account, as well as their calculated values. This paper describes a methodology for determining these values. The examples are given on how to calculate the main meteorological characteristics of the percentage of integral probability, which are used in designing, constructing and maintaining roads.

In recent decades Lithuania has witnessed an increase in road construction and reconstruction works involving the use of geosynthetics, which is usually concerned with special functions. One of them is separation of layers of aggregate by geotextile in the structure of road pavement. To successfully implement the separation, there are several crucial factors to be taken into consideration: the integrity, durability of the material and damages identified during installation. In Lithuania the geosynthetics is selected on the basis of eight-year-old interim guidelines and recommendations of suppliers. The paper deals with the systems of selecting geosynthetics in Lithuania and other countries. Then the results of experimental research are assessed. The present research has selected 5 types of geosynthetics of some manufacturers. The geotextiles were installed between different layers of road pavement structure. The analysis focuses on geotextile damages emerging during installation and their impact on performing the function of separation.

Traffic safety situation in Lithuania, despite the progress made in 2008, is still not good enough compared to the other European Union countries. Therefore, Lithuania implements the traffic safety improvement measures affecting all the elements of the traffic safety system “Road user‐road‐vehicle”. In 2008 Lithuania started implementing the road safety audit procedure which substantially contributes to the improvement of safety situation on Lithuanian roads. This article gives the analysis of road safety audits of special plans and technical designs for road construction and reconstruction in Lithuania, makes the analysis of the main deficiencies of plans and designs and gives recommendations for their elimination. Santrauka Eismo saugumo situacija Lietuvoje, nepaisant 2008 m. pasiektos pažangos, vis dar yra nepakankamai gera, palyginti su kitomis Europos Sąjungos šalimis. Atsižvelgiant į tai, Lietuvoje įgyvendinamos eismo saugumo gerinimo priemonės, darančios įtaką visiems eismo saugumo sistemos „Eismo dalyvis–kelias–transporto priemonė“ elementams. Lietuvoje 2008 m. buvo pradėta taikyti kelių saugumo audito procedūra, kuri prisideda prie eismo saugumo gerinimo Lietuvos automobilių keliuose. Straipsnyje pateikta Lietuvoje atliktų specialiųjų planų ir automobilių kelių tiesimo bei rekonstrukcijos techninių projektų kelių saugumo auditų analizė, išanalizuoti pagrindiniai planų ir projektų trūkumai, pateiktos rekomendacijos jiems šalinti. First Published Online: 15 Oct 2010 Reikšminiai žodžiai: eismo saugumas keliuose, eismo įvykiai, kelių saugumo auditas.

The Lithuanian climatic conditions set high requirements for road and street maintenance in winter. In our country, the air temperature is below zero for 3–4 months per year. The longest period of this temperature is in eastern Lithuania, and the shortest period is in the coastal area. On average, the first snow cover forms from the middle of November and remains until the middle of March. Moreover, in winter thaws are frequent in Lithuania and the temperature fluctuates around zero. There is also high probability of glazed frost, freezing rain and fog. In most European countries road weather information systems have been established. The aim of these systems is to reduce the road maintenance costs in winter, to ensure good traffic safety, to inform drivers about poor traffic conditions. The following main components make up the integrated road weather information system: a) spatial analysis of the road microclimate to produce temperature graphs; b) road pavement and atmospheric characteristics’ sensors providing information on the actual weather conditions on the roads; c) computer and information network. The road engineer receives all information in a form which enables to use it quickly and take necessary actions. It also enables to collect external data on the weather conditions, which, upon its statistical analysis, can be used for road design, construction, repair and maintenance.

The article presents three-system modelling of road pavement deterioration used in Lithuania: HDM-III (Highway Design and Maintenance Standards Model), HDM-4 (Highway Development and Management System) and DAVASEMA—Lithuanian pavement management system developed by Lithuanian Road Administration and based on HDM-III models. Using research data gathered in four years of the programme the authors analyse possibilities of adapting the pavement deterioration models to Lithuanian conditions. The article describes suggested procedures for calculating of calibration coefficients for the pavement deterioration models of the highest importance: road roughness component incremental model, structural cracking initiation model and structural cracking progression model. Frist Published Online: 30 Jul 2012

This article deals with the design problems of gravel road pavements. Mathematical models related to geological and hydrological conditions of a location, thickness of gravel pavement and characteristics of the gravel contained in this pavement are proposed to be used for pavements. For the selection of gravel pavements for reconstruction we recommend the models developed by the method of experimental planning to calculate the equivalent deformation modulus of the gravel pavements change depending on the deformation modulus of the subgrade, thickness of the gravel pavement and the materials used for its layers. Practical applications of these models will eliminate the mistakes that are still found in road pavement design. Frist Published Online: 30 Jul 2012

The article describes the main problems of manufacturing asphalt concrete mixtures at the factories under Ministry of Communication in the Republic of Lithuania. The Lithuanian Road Network is up to 21.122 km of state roads. 1.455 km of them are motorways, 3.415 km—national roads and 16.251 km—regional roads. Half of the state roads in Lithuania are paved with asphalt concrete. 98% of the motorways and 36% of the regional roads have asphalt pavement. Asphalt concrete pavement resistance to corrosion can be increased by improving asphalt concrete mixture production technology: ie by updating technological equipment, changing technological conditions and developing new methods of asphalt concrete mixture production. Therefore, the updating of asphalt concrete mixture production technologies is a very important factor for improving road operating properties and ensuring proper duration of asphalt concrete pavements. Here is the essence of the new separate successive technology: crushed stone and sand are mixed with bitumen in the main asphalt concrete mixer, the amount of bitumen being calculated according to the bitumen absorption in the materials. Then the asphalt cement material produced in a separate high-speed mixer is passed, and the whole mixture is remixed in the main mixer and supplied to the customer. Both separate consequent technologies differ from each other in the order of supplying asphalt cement material into the main mixing unit. Separate successive technology was theoretically grounded by the correlation between the technological thickness of bituminous film and the chemical-mineralogical composition and size of constituents, by the correlation between the particle size and their capability to compose aggregates, by the emergence of the oriented binding material coating on the technological bituminous film encoating mineral particles. Special attention is given to the manufacturing of asphalt cement material in a separate high-speed mixer (3 Table). It was theoretically grounded that mineral filler passing through the intensive shift zone between the paddle ends of the high-speed mixer and the walls of mixing chamber disintegrate and new active surfaces become visible. The molecular structure changes and free radicals appear. This intensive mixing guarantees high bitumen adsorption on the surface of mineral filler, which increases asphalt concrete resistance to corrosion and its durability, improves ecological environment in the asphalt concrete plant. In order to confirm the reliability of research results and explain correlative and regressive regularity, statistical data were processed applying statistical data processing programming system “STATGRAPHICS”. The linear regressive analysis for determining close relations of separate asphalt concrete quality indicators with speed gradient of asphalt cement material shift in a high-speed mixer was performed. Therefore, the possibility to change shift speed gradient from 3000 to 5000 1/s is provided in terms of reference for manufacturing asphalt concrete mixing plant. Correlation between separate asphalt concrete quality indicators and asphalt cement material shift speed gradient as well as bitumen amount in the asphalt cement material was determined by multi-dimensional regressive analysis of experimental data. The calculated correlation factor squared (R2) and F criteria indicate the adequacy and reliability of the multidimensional regression model. First Published Online: 26 Jul 2012