The 4th International Conference on Road and Rail Infrastructure – CETRA 2016 was organized by the University of Zagreb – Faculty of Civil Engineering, Department of Transportation.The Conference is held in Šibenik, Croatia. Šibenik is the first town in the world to benefit from electric lighting. In fact, on 28 August 1895, the alternating current electric lighting was activated for the first time in the streets of Šibenik. The merit for this certainly goes to the inventor, visionary genius and researcher of Croatian descent, Nikola Tesla, whose alternating current discovery lighted up streets and squares of Šibenik. The Šibenik power plant was the first alternating current power system in Croatia, the first commercial hydro power plant in Europe, and the second one in the world. It was put in operation on 28 August 1895 at 20:00, two days after the Adams Power Plant on the Niagara Falls. The 1st International Conference on Road and Rail Infrastructure – CETRA 2010 is held 17-18 May 2010 in Opatija. The 2nd International Conference on Road and Rail Infrastructure – CETRA 2012 is held on 7-9 May 2012 in Dubrovnik. The 3rd International Conference on Road and Rail Infrastructure – CETRA 2014 is held on 28-30 April 2014 in Split. Great interest of participants in topics from the field of road and rail infrastructure during the previous conferences CETRA, confirmed the soundness of Department for Transportation Engineering’s decision on organizing such international event. Positive comments of the participants after the past Conferences motivated the Department for Transportation Engineering, Faculty of Civil Engineering at University of Zagreb to continue the organization of such an international event. The CETRA conference has established itself as a venue where scientific and professional information from the field of road and rail infrastructure is exchanged. The idea on linking research organisations and economic sector has been the guiding concept for the realisation of this conference. Conferences of this kind are undoubtedly a proper place for bringing closer together the economy and university operators, and for facilitating communication and establishing greater confidence that might result in cooperation on new projects, especially those that contribute to greater competition. Lectures organized in the scope of the conference are based on interesting technical solutions and on new knowledge from the field of transport infrastructure as gained on already realised projects, projects currently at the planning stage, and those now under construction, in all parts of the world. In addition to authors from the academic community, lectures were also presented by practical authors, the idea being to ensure the best possible synergy between the theory and practice. Because of a great interest for the themes from the field of road and rail infrastructure, as shown during the past two conferences (CETRA 2010, CETRA 2012 and CETRA 2014), the Department for Transportation Engineering of the Faculty of Civil Engineering – Zagreb assumed the responsibility to organise the CETRA conference in this year as well. Our goal for the International Conference on Road and Rail Infrastructure – CETRA is to have all published papers indexed in scientific databases in order to achieve greater recognition for the conference itself, for published papers, and for their authors. As the serial publication entitled Road and Rail Infrastructure has been achieved with last conference (CETRA 2014), the precondition has been fulfilled to obtain the International Standard Serial Number (ISSN), which was the condition for starting procedure for registering this publication in scientific databases. A great novelty is that the CETRA 2016 conference will be indexed in the TRID base, which is an integrated database that combines the records from TRB’s Transportation Research Information Services (TRIS) Database, and the OECD’s Joint Transport Research Centre’s International Transport Research Documentation (ITRD) Database. TRID provides access to more than one million records of transportation research worldwide. In addition, the TRID base has accepted all papers that were published at previous CETRA conferences. In the year 2016, 4th International Conference on Road and Rail Infrastructure – CETRA 2016 has been organized, with the intention of bringing together scientists and experts in the fields of road and railway engineering, giving them another opportunity to present the results of their researches, findings and innovations as well as to analyze problems encountered in everyday engineering practice and to offer possible solutions for a more efficient planning, design, construction and maintenance of transport infrastructure. Conference CETRA 2016 covers many areas: Traffic planning and modelling, Infrastructure projects, Infrastructure management, Road pavement, Rail track superstructure, Construction and maintenance, Transport geotechnics, Tunnels and bridges, Structural monitoring and maintenance, Computer techniques and simulations, Noise and vibration, Innovation and new technology, Urban transport, Integrated timetables on railways, Vehicles dynamics, Traffic safety and for the first time Traction Vehicles and Power Supply of Transport Systems. This Conference CETRA 2016 attracted a large number of papers and presentations from 37 countries and 54 Universities. More than 140 papers were presented at the Conference and are contained in these proceedings Road and Rail Infrastructure IV. The organizers of the Conference express their thanks to all Businesses and Institutions which support this Conference. Special thanks are extended to the European Railway Agency (ERA), for their assistance and support in organizing very important conference sessions regarding Interoperability of the European rail system especially regarding 4th Railway Packages issues and Technical Specifications for Interoperability (TSI). The objective of ERA is to contribute, on technical matters, to the implementation of the European Union legislation aimed at improving the competitive position of the railway sector by enhancing the level of interoperability of railway systems, developing a common approach to safety on the European railway system and contributing to creating a Single European Railway Area without frontiers, guaranteeing a high level of safety. The Editor commends all authors for excellent papers contributed to these proceedings, and wishes to thank members of the International Academic Scientific Committee, and numerous experts who participated in the review process. The gratitude is also extended to all participants for deciding to come to Šibenik and take part in CETRA 2016. We believe that these CETRA 2016 proceedings entitled Road and Rail Infrastructure IV will be, just like the preceding three proceedings from the CETRA cycle, highly interesting and useful to all experts exhibiting a scientific and professional interest in road and rail infrastructure.