Multi-criteria Analysis of Indicators of the Public Transport Infrastructure

Public transport is a key element of sustainable transport in medium and large cities. Therefore, it is important that city residents want to use it. This paper aims to determine the criteria of the public transport infrastructure which have the most influence on passenger satisfaction with the public transport system. The criteria of public transport infrastructure of stops, vehicles, and route network were analysed. The primary attention was focused on rating these criteria from the most to the least important one. The analysis of scientific papers, specialized literature, Europe Union regulations, Lithuanian legislation, and recommendations were used to explore the necessary criteria that have a significant effect on the popularity of public transport, its functionality and gives a reference on how to raise the willingness of the citizens to use public transport. The experts (14 experts were involved) and social surveys (440 respondents were involved) were used to identify the evaluation criteria of public transport infrastructure and to investigate the state of these criteria. These criteria were grouped into three larger groups according to their nature (public transport infrastructure of stops, vehicles and route network) and were rated and prioritized by the multi-criteria analysis. The results reflect the priorities of criteria parameters of public transport infrastructure. The results show that when investing in public transport infrastructure, the main priority should be attributed to the infrastructure elements, such as public transport priority in the streets, then shelters, lighting, cleanness of bus stops and vehicles, which are physically appreciable. These parameters have the most significant impact on improving the level of service of public transport infrastructure in urban areas.</p

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

Preliminary Study on Runway Pavement Friction Decay Using Data Mining

AbstractSurfaces of airport pavements are subject to the friction decay phenomenon. A recurrent problem for the runways is represented by the deposits of vulcanized rubber of aircraft tires. This happens mainly in the touch-down areas during landing operations, and the loss of grip compromises the safety of both take-off and landing operations. This study moves from the International Civil Aviation Organization and the Italian Civil Aviation Authority provisions concerning runway friction measurement and reporting to a better way to analyze friction data. Being data mining the computational process of discovering patterns in a large data sets, data mining techniques are very helpful to reach this target. Unsupervised and supervised classification methods to analyze friction data detected by Grip Tester Trailer were employed. First, K-means and Subtractive Clustering were applied to divide data into a certain number of clusters representing the different areas of consumption. In a second time two different Classification and Regression Trees models, CART and GCHAID, were employed to split the data points of the runway into nodes. At the end of the process scatterplots were built and better visualized through non-linear regressions. The decay curves obtained were of service to compare the results achieved using data mining techniques versus the International Civil Aviation Organization and the Italian Civil Aviation Authority provisions in order to find out the best way to analyze friction data. The final goals are to assure an optimum scheduling of the Airport Pavement Management System, as well as users safety

Modern Roundabouts: A Challenge of the Future

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Comparison study of spherical and multi-spherical particles under cyclic uniaxial compression

Numerical simulation of cyclic compression of granular material by performing oedometric test has been performed. Discrete Element Method (DEM) has been employed for simulation. A comparison study has aimed to examine the differences in macroscopic behaviour of material discretized by spherical (S) and non-spherical shape models of a particle. During the study, microscopic data of sand from Klaipėda were used for modelling the shape of particles. The nonspherical particles were described by multi-spherical (MS) models retaining distributions for size and aspect ratios. Two DE models of tested specimens were developed and the deformation behaviour under cyclic uniaxial compression was simulated numerically by applying the commercial EDEM code. The variation of the oedometric elasticity modulus was investigated and influence of particle shape on void ratio changes was demonstrated. It was clearly shown that application of S particles is much more sensitive to rearrangement of particles during densification DEM. Simulations illustrated that the elasticity modulus of material corresponding to MS particles is approximately 1.9 times larger comparing with material corresponding to S particles. Therefore, one must improve the magnitude of elasticity modulus by introducing a respective correction factor

Understanding the Walkability Propensity

Walkability analysis has grown in popularity in recent years: several studies have analysed the public health, economic, environmental, transportation and other benefits of promoting walkability. Different authors in the literature focus on the analysis of walking indicators related to the structure of the road network to explain the walkability of an area. However, extra efforts have to be made to study many other conditions that affect the propensity to walk: not just the shape of the network and the urban topology, but also the security and the attractiveness of the landscape, or specific characteristics of the infrastructure such as the size of the sidewalks, the automobile accommodation values (automobile and motorcycle parking) and the pedestrian route difficulty (slope and over length of the paths, dead-end streets). This paper aims to understand the walkability propensity, investigating explanatory variables related to the concept of the pedestrian path quality at the microscopic level. Several data have been collected in different zones of the Rome City (Italy), utterly dissimilar from the pedestrian point of view. These data have been compared with the real path for pedestrian choices and with other standard walkability measures from literature

Mineralinių medžiagų mechaninių savybių tyrimai, analizė ir vertinimas / Research, analysis, and evaluation of mechanical properties of aggregates

The two Baltic countries, Lithuania and Latvia, use asphalt mixtures with granite slag that is imported from other countries to install the top layer of asphalt pavement, which is quite expensive. One of the requirements for aggregates used in road construction is mechanical properties. There are some differences between these countries based on national requirements. The article presents test methods for determining the mechanical properties of aggregates. According to them, the mechanical properties of aggregates were tested: resistance to fragmentation, wear, polishing and to wear by abrasion from studded tyre. Tested aggregates were Lithuanian dolomite quarry stone, which was made based on the developed and common technologies as well as imported granite from Ukraine. The analysis and evaluation of the test results have been carried out by the requirements for mineral aggregates of Lithuania and Latvia. Santrauka Dvi Baltijos šalys, Lietuva ir Latvija, asfalto dangos viršutiniam sluoksniui įrengti naudoja asfalto mišinius su granito skalda, kuri importuojama iš kitų šalių, o tai gana brangu. Vienas iš reikalavimų mineralinėms medžiagoms, naudojamoms kelių tiesyboje, yra mechaninės savybės. Jos minėtose šalyse pagal nacionalinius normatyvinius reikalavimus šiek tiek skiriasi. Straipsnyje pateikti mineralinių medžiagų mechaninių savybių nustatymo bandymo metodų aprašai. Pagal juos atlikti skaldų mechaninių savybių bandymai: atsparumas smūgiams, trupinimui, dėvėjimuisi, poliruojamumui (LST EN 1097-8:2009. Bandymai užpildų mechaninėms ir fizikinėms savybėms nustatyti. 8 dalis. Akmens poliruojamumo nustatymas) bei dygliuotoms padangoms. Ištirtos skaldos yra Lietuvos dolomito karjero skalda, pagaminta pagal patobulintą ir įprastą technologijas, bei granito skalda iš Ukrainos. Atlikta gautų bandymų rezultatų analizė bei vertinimas pagal Lietuvos ir Latvijos reikalavimus mineralinėms medžiagoms. Reikšminiai žodžiai: atsparumas smūgiams, trupinimui, dėvėjimuisi, poliruojamumui bei dygliuotoms padangoms, dolomitas, granitas, mechaninės savybės

Analysis and evaluation of the economic effect of asphalt mixtures AC 11 VS and SMA 11 S with different graded aggregates

The European building sector is facing a pressing issue of natural resources. Importing road building materials for the asphalt surfacing increases the cost of the asphalt mixture. The asphalt surfacing mixtures shall consist of a mixture of graded aggregates accounting for 80−90% of the total volume of the asphalt mixture, or 90−96% of the total weight of the asphalt mixture and binder: road bitumen or polymer modified bitumen. In the Republic of Lithuania, asphalt mixes are designed in accordance to the Design Regulations for Road Pavement Standardized Pavement Structures KP SDK 19 and accordance to the normative documents and their requirements for graded aggregates and binders. Road builders import graded aggregates to asphalt mixes from other countries, and this increases the cost of asphalt mixes. According to the scientific researches in the Lithuanian quarry Petrašiūnai II, using unique production technology is produced class I dolomite crushed stone, which mechanical, physical properties and designed asphalt mixtures can replace imported graded aggregates. The economic question remains as to the economic effect of the most commonly used asphalt mixtures in Lithuania AC 11 VS (asphalt mixture of asphalt&nbsp;pavement wearing course) and SMA 11 S (crushed and mastic asphalt) made from indigenous minerals compared to imported minerals. The aim of the paper is to perform the calculation and evaluation of the economic effect of asphalt mixtures AC 11 VS, SMA 11 S with different minerals and micro-aggregate. The paper identifies and analyses the properties of asphalt test mixtures, and identifies the locations of mineral suppliers in Lithuania. According to the economic impact assessment scheme, the economic effect of asphalt mixtures AC 11 VS, SMA 11 S with different minerals and micro-aggregate was calculated. According to the calculations made, the economic effect of producing asphalt mixtures AC 11 VS, SMA 11 S with class I dolomite chips is 13−14%. Article in Lithuanian. Asfalto mišinių AC 11 VS ir SMA 11 S su skirtingomis mineralinėmis medžiagomis ekonominio efekto analizė ir vertinimas Santrauka Europos statybos sektoriuje yra aktualus gamtinių išteklių klausimas. Importuojant kelių tiesybos medžiagas asfalto viršutiniam sluoksniui įrengti, didėja asfalto mišinio kaina. Asfalto viršutinio sluoksnio mišiniai susideda iš mineralinių medžiagų mišinio, sudarančio 80−90&nbsp;% viso asfalto mišinio tūrio, arba 90−96&nbsp;% visos asfalto mišinio masės ir rišiklio: kelių bitumo arba polimerais modifikuoto bitumo. Lietuvos Respublikoje asfalto mišiniai projektuojami remiantis Automobilių kelių standartizuotų dangų konstrukcijų projektavimo taisyklėmis KP SDK 19 bei pagal normatyvinius dokumentus ir juose pateiktus reikalavimus mineralinių medžiagų mišiniams bei rišikliams. Asfalto mišinių gamybai naudojamas mineralines medžiagas kelių tiesėjai importuoja iš kitų valstybių, bet tai pakelia asfalto mišinių kainą. Pagal atliktus mokslininkų tyrimus Lietuvos karjere Petrašiūnai&nbsp;II, naudojant specialią gamybos technologiją, gaminama I klasės dolomito skalda, kurios mechaninės, fizikinės savybės bei suprojektuoti asfalto mišiniai gali pakeisti importuojamas mineralines medžiagas. Lieka aktualus klausimas, koks ekonominis efektas Lietuvoje dažniausiai naudojamų asfalto mišinių AC 11 VS (asfalto viršutinio sluoksnio asfaltbetonio mišinys) ir SMA 11 S (skaldos ir mastikos asfaltas), pagamintų iš vietinių mineralinių medžiagų, lyginant su įvežtinėmis mineralinėmis medžiagomis. Straipsnio tikslas&nbsp;– atlikti asfalto mišinių AC 11 VS, SMA 11 S su skirtingomis mineralinėmis medžiagomis bei mikroužpildu ekonominio efekto skaičiavimą bei vertinimą. Straipsnyje nustatomos ir analizuojamos asfalto bandomųjų mišinių savybės, nurodomos mineralinių medžiagų tiekėjų vietos Lietuvoje. Pagal ekonominio efekto vertinimo schemą apskaičiuotas asfalto mišinių AC 11 VS, SMA 11 S su skirtingomis mineralinėmis medžiagomis bei mikroužpilu ekonominis efektas. Vertinant atliktus skaičiavimus, gauta, kad gaminant asfalto mišinius AC 11 VS, SMA 11 S su I klasės dolomito skalda ekonominis efektas sudaro 13−14&nbsp;%. Reikšminiai žodžiai:&nbsp;asfalto mišinys, I klasės dolomito skalda, granitas, mikroužpilas, mineraliniai milteliai (aktyvintieji)

Assessment of Skid Resistance of Road Pavements

The quality of the paved road depends not only on the decisions of the road designer and the work carried out but also on the materials used. Most of the aggregates used are imported from other countries. However, the usage of domestic materials reduces the cost of the road pavement and the use of aggregates produced by a special production technology in Lithuania, i.e., dolomite aggregates instead of granite aggregates. Experimental studies were carried out on the skid resistance of the road surface. It was found that the coefficient of skid resistance met the requirements for surface dressing with dolomite aggregate, and the results were analysed with 95% probability. This coefficient partially met the requirements for asphalt concrete, while it did not meet the requirements at all for stone mastic asphalt. The surface roughness, however, met the requirements for road sections where granite aggregates were used instead of dolomite in mixes of surface dressing and asphalt concrete. The analysis was carried out considering the volume of traffic and the service life of the individual road sections. It was determined that it was suitable for a 5-year guarantee period to perform the surface dressing, wearing course of asphalt concrete and stone mastic asphalt with dolomite aggregate where part of heavy vehicles is less than 20% of traffic flow. The use of granite aggregates was justified only in the road where heavy vehicles dominated

Evaluation of Shoulders Functions on Lithuanian Regional Roads

Granular shoulder is an important element of road system. One can frequently notice shoulders rutting, edge breakage, unconformity of cross-section to the norms that could be caused by wind and water-generated erosion. These problems directly affect the drivers, influences their behaviour on the road and traffic safety. Therefore, a constant maintenance of road shoulders is necessary. Investigations of the Lithuanian gravel road network showed that the lowvolume roads with gravel surfacing do not correspond to the current standards and the change in their performance due to climatic conditions, traffic volume and the materials used for the structures have a large influence not only on traffic safety but also on traffic conditions. It is very important for the road shoulders to improve traffic safety, to prevent road carriageway edges from degradation, to serve for emergency parking and for the installation of guardrails, warning and informatory signs. Since shoulder deformations are caused by the deformations in the subgrade and its slopes, a properly prepared and erected subgrade should be provided with the shoulder of corresponding structure where inadmissible deformations would not occur. Defects in the low-volume road pavement occur when gravel of unsuitable composition is used for the shoulder pavement, the structure is of insufficient thickness and strength, the top of the subgrade becomes damp due to the lack of proper drainage or road maintenance is of unsatisfactory level. It is very important for the shoulders of low-volume roads to use a proper material for increasing the structural strength of the shoulder and preventing it from defects