This article has an aim to review the range and value of the underground resources of the Republic of Lithuania, to analyse the quality of local aggregates used for road building purposes and to recommend how local aggregates have to be used in order to give the max benefit for the state and public welfare. All the investigated in detail mineral resources of the Republic of Lithuania make almost one third of the value of the property the country. All the deposits of dolomite, gravel and sand explored in detail and used for road building, construction and other purposes occur under the less than 0.1% of the territory of the country. It was found that extraction and processing of local dolomite and gravel resources up to the max use of their potential properties for road building and other purposes saves over 700 mln LTL (over 200 mln EUR) per year in the cash flow of the Republic of Lithuania. It was determined that the physical and mechanical indices of asphalt concrete, containing crushed pebble and crushed dolomite, differ insignificantly. Based on the comparison to the normative requirements, local aggregate products consumption in asphalt concrete could be increased by extra 8-10% compared to the use of imported materials. It was recommended, that various subbase material mixtures from local, imported or mixed compositions were extra tested and analysed after at least of 350-700 freezing and thawing cycles corresponding to the average of 10-20 years subbase service under Lithuanian mild winter climate conditions with a high number of freezing and thawing cycles. The article gives a complex analysis of the research results versus the condition of the underground mineral resources and presents conclusions valuable for both geologists, road building scientists and engineers as well as decision makers finalising The Strategy for the Optimum Use of Lithuanian Underground Mineral Resources potential and implementing the Communications of the European Commission the Raw Materials Initiative -Meeting our Critical Needs for Growth and Jobs in Europe and Improving Framework Conditions for Extracting Minerals for the EU.

International cooperation and close relations with scientific institutions assist the Lithuanian Road Administration under the Ministry of Transport and Communications of Lithuania in implementing the policy of road network development, road building and maintenance, infrastructure development, and traffic safety organization. Fostering of cooperation in the region and abroad, exchange of best practices, improvement of professional skills, also the scientific research works and studies and dissemination of their results play an important role in the improvement of road infrastructure. The article outlines representation of Lithuanian Road Administration in international road organizations and the main fields of its scientific activities and research.

Road are significant national assets which provides a fundamental foundation to the performance of all national economies, delivering conditions for social and economic development of countries and international communities. It is of at most importance to ensure a mobile and safe movement of inhabitants with the lowest time and pollution costs. In order to reach the goals the planning processes are implemented on a national and international scale to rationally justify the efficiency of urgent measures. In the Republic of Lithuania, seeking to efficiently use funds allocated to the road sector the Road Maintenance and Development Programmes are developed by the road manager defining a short-term and long-term vision of the road network and measures to achieve it. However, due to the anticipated insufficient financing of the road sector the Road Maintenance and Development Programmes aim to rationally combine preservation of the road network and its perspective development depending on the existing financing. The Road Maintenance and Development Programme of the Republic of Lithuania for 2030 assesses the existing condition of the road network and defines the goals and measures how to implement a sustainable development in the road network. With the help of review analysis this paper studies: road safety assurance, road pavement deterioration degree, social welfare assurance, road maintenance, infrastructure development, assurance of sustainable development.

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Straipsnyje pateikiami ir analizuojami Lietuvos žvyrkelių techninės būkles tyrimų rezultatai. Moksliškai pagrindžiamas dangos lygumo—svarbiausio žvyrkeliij būklės techninio bei ekonominio rodiklio—taikymas žvyrkelių asfaltavimo ekonominiam tikslingumui vertinti. Asfaltinės dangos įrengimo tikslingumui nustatyti žvyrkeliuose buvo atlikti eismo stebėjimai, kelio pločio, žvyro dangos sluoksnio storio, žvyro misinio granuliometrinės sudėties, molio, dulkių ir dumblo kiekio, vandens nuleidimo sistemos įrenginiq, kelio sankasos buklės, reikalingo sustojimo matomumo bei dangos lygumo tyrimai. Pažymima, kad tyrimuose pirmą kartą Lietuvoje žvyro bei asfaltinės dangos lygumas buvo nustatytas pagai tarptautinę nelygumų indekso IRI skalę. Tyrimų duomenij pagrindu apskaičiuota žvyro dangos nelygumų didėjimo, išlyginus greideriu, kreivė, taikytina vidutiniam žvyrkelio lygumui nustatyti. Antroje straipsnio dalyje aprašomas teoriniais bei eksperimentiniais tyrimais pagrįstas Lietuvos ekonomines bei klimatines sąlygas atitinkantis žvyrkelių renovacijos ekonominio tikslingumo vertinimo modelis KAMIS. Pateikiami trumpi išlaidų bei santaupų submodelių bei modelio esmės aprašymai, modelio matematinė išraiska ir algoritmo schema. Nustatytas pagrindinis žvyrkelių renovacijos ekonominio tikslingumo vertinimo kriterijus riboto biudžeto sąlygomis—vidinės grąžos norma. Tyrimų metu gauti tarpiniai rezultatai Lietuvos kelių įmonėse naudojami nuo 1995 m., o modelis įdiegtas 1997 m. Pagai KAMIS, 1997 bei 1998 metų žvyrkelių asfaltavimo programų bendras ekonominis efektas 20-ies būsimų metų laikotarpiu 1997 m. kainomis turėtų viršyti 174 mln.Lt.