Design solutions for lithuanian gravel road pavements

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 201

Adaptation of pavement deterioration models to Lithuanian automobile roads

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 201

Assessment of special plans and technical designs with regard to traffic safety

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

Traffic Calming Measures: An Evaluation of the Effect on Driving Speed

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.</p

Definition of concrete and composite precast concrete pavements texture

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

Research of snow melting materials performance efficiency for road winter maintenance

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

Main problems of manufacturing asphalt concrete mixtures in Lithuania/Asfaltbetonio mišinių gamybos svarbiausios problemos Lietuvoje

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 201

Electronic road toll system and its installation on Lithuanian roads

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

Road Climatology: Determination of Calculated Values of Meteorological Characteristics

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

Analysis of Older Pedestrian Accidents: A Case Study of Lithuania

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