People
prof. Ing. Pavel Přibyl, CSc.

2022, INTERNATIONAL JOURNAL OF ENGINEERING, 35 (5), p. 900-907), ISSN 1025-2495

Road construction and maintenance activities cause traffic congestions and delays and present challenges for ensuring the safety of both motorists and road workers. While urban areas are well-equipped with traffic devices, in the case of highways our chances to collect traffic data and control traffic flows may be limited. Then the use of a temporary Highway Traffic Management System seems to be a suitable solution. Although the impacts of its deployment are addressed by many theoretical studies and demonstrated on traffic simulation models, there are not many references dealing with field tests. We provide results of the practical evaluation of the temporary Highway Management System installed and tested on the main highway in the Czech Republic during the road works period. Before-after analysis of collected traffic data was performed to prove the importance and positive impact of the proposed solution. We demonstrate an over 20% increase in the capacity of the roadwork zone and an almost 30 seconds decrease in average delay for one vehicle Highway administrators can use the results to justify investments into the temporary deployment of mobile traffic management systems.

2022, PIARC 2nd International konference on road tunnel operations and safety, Paris La Défense cedex, World Road Association (PIARC) Technical Committee C.3.3), p. 981-995), ISBN 978-84-95641-48-9

The widely accepted body, The World Road Association (PIARC), has published research that up to 60% of future road tunnel operating costs can be saved by optimizing the tunnel design at an early stage of project implementation [1]. The paper shows the paradigm of recent years – more and more innovative technologies for tunnels do not necessarily mean that the functions for which tunnels are built are performed more efficiently. A road tunnel is a complex system created as a pragmatic alliance of several subsystems and many devices from different suppliers. Tunnel documentation usually has several hundred pages prepared by specialists in ventilation, lighting, safety, etc., and it is difficult for the investor or administrator to optimize the equipment without a detailed model of this complex system. There are two models for describing a complex system: a process model and a knowledge model. The paper shows that a more suitable model for describing a tunnel system is an ontology-based knowledge model and gives an example of such a model.

2021, Applied Sciences, 11 (22), ISSN 2076-3417

owadays, urban road tunnels are considered to be independent entities within a city. Their interactions with the rest of the city and vice versa are usually not considered and, if they are, are only considered in a limited way (for example, through the nearest traffic controller). Typically, only the traffic parameters and not the environmental impacts are considered. This paper has two major objectives. First, we provide a systemic view on a road urban tunnel. The major focus is on the interfaces between the tunnel and the rest of the city and the way they will be managed. We are providing a tool to take into consideration a sustainable development of a tunnel (i.e., not only traffic flow parameters such as average speed, but also environmental and societal characteristics). This model expresses the actual traffic situation in a monetary form (i.e., cost of congestions). The second objective is to provide a new road urban tunnel control approach that follows the original methodology and systemic view described in the paper. If the tunnel is controlled autonomously, which corresponds to the current state-of-the-art in many cities, the algorithm decides to close it based on only local parameters. However, the proposed new algorithm takes into consideration not only the traffic situation in the tunnel (expressed by the parameter traffic density), but also the actual traffic situation within the city (expressed by its level of service (LOS)). This allows more environmentally, socially and economically sustainable oriented road urban tunnel management. The described algorithm is demonstrated on a specific example of the tunnel complex Blanka in Prague.

2020, Research and the Future of Telematics, Basel, Springer Nature Switzerland AG), p. 152-164), ISBN 978-3-030-59269-1, ISSN 1865-0929

Smart city has several definitions. Typically, it is an alliance of subsystems that have following objectives: improvement of quality of life of citizens, better use of limited resources and best use of existing infrastructure. Transportation as one of the most important subsystems shall be thus understood as one player working together with energy management, economy, eGovernment, and others. Synergy is the key to successful implementation. In order to be able to aim at the joint objective function and any synergy, the different subsystems must “understand” each other. Ontology has been acknowledged to be the most common tool to do that. To prepare an ontology for a domain (for example transportation) is a complicated task. In order to do that in a city, where there are several subsystems with complex behaviour is even more challenging. It is very difficult if not impossible to get experts from different fields to prepare a common ontology. In this paper we address the issue of Smart City Design and propose a pragmatic method to prepare an ontological knowledge system using the knowledge of various expert groups. A new concept, so call a knowledge matrix, is defined and used to enable cooperation of experts from different fields. We believe this can further help in implementation of any smart city projects. In order to demonstrate the approach, transportation domain is used as an example for the ontology design. The approach will be further validated within two case studies that are also introduced within this paper: Smart Evropská street in Prague and within a project Smart City – Smart Region – Smart Community, where a transport behavioristic model is being developed based on the ontology described within this paper.

2019, IEEE Intelligent Transportation Systems Magazine, 11 (4), p. 28-36), ISSN 1939-1390

Nowadays the term Smart City is widely used and almost every city aims to become “Smart”. Unfortunately, the definitions of what Smart means differ and there is not a single accepted one. Often a technocratic view is adopted and the actual goal—make city more liveable—is not kept in mind. In this paper, a new approach to initiate and develop Smart City model is provided. A unified model is one way to describe the processes within such complex and heterogeneous system as Smart City. It is based on the similarity to the well-established framework called ITS (Intelligent Transport System) architecture. First, an overview of the Smart City initiatives and key principles that often require change of the way how we think of projects is provided. Further, the objectives and approach to national ITS architectures are described and discussed, mainly aiming on its limitations for the practical use especially in the context of Smart Cities. Finally, this paper provides a guidance on how a Smart City Architecture shall be established to overcome the system complexity and to reduce its dimension in terms of volume of required data flow. The new approach is based on decentralized intelligence, where a number of processes are carried out at the level of so-called building blocks. Multi-agent systems are proposed as a design tool for the particular building blocks.

2018, Structural Monitoring and Maintenance, 5 (3), p. 363-377), ISSN 2288-6605

The proper functioning of critical points on transport infrastructure is decisive for the entire network. Tunnels and bridges certainly belong to the critical points of the surface transport network, both road and rail. Risk management should be a holistic and dynamic process throughout the entire life cycle. However, the level of risk is usually determined only during the design stage mainly due to the fact that it is a time-consuming and costly process. This paper presents a simplified quantitative risk analysis method that can be used any time during the decades of a tunnel’s lifetime and can estimate the changing risks on a continuous basis and thus uncover hidden safety threats. The presented method is a decision support system for tunnel managers designed to preserve or even increase tunnel safety. The CAPITA method is a deterministic scenario-oriented risk analysis approach for assessment of mortality risks in road tunnels in case of the most dangerous situation – a fire. It is implemented through an advanced risk analysis CAPITA SW. Both, the method as well as the resulting software were developed by the authors’ team.

2018, Communications - Scientific Letters of the University of Žilina, 20 (3), p. 9-14), ISSN 1335-4205

The paper is focused on the influence of driving behaviour on fuel consumption and the subsequent environmental impacts. The main issue is to estimate the economic and environmental costs connected with the forced deceleration or stopping and the subsequent acceleration of a motor vehicle in urban traffic. Authors introduce a physical model of a vehicle with variable parameters that allows the calculation of economic and ecological losses in congestions on the basis of data generated by an arbitrary floating car. The losses include the lost kinetic energy of a vehicle during the forced braking, accelerated degradation of vehicle components, the loss of time of drivers and passengers and the increased ecological footprint. Energetic costs are estimated from the vehicle engine efficiency with which the fuel energy is transformed during an acceleration to kinetic energy of a vehicle lost during braking. Further, these costs are estimated from fuel calorific value and fuel price. Costs resulting from the degradation of vehicle components are estimated from their average stated lifetime.

2018

2017, Tunnelling and Underground Space Technology, 69, p. 28-36), ISSN 0886-7798

Safety is one of the most important aspects when designing a road tunnel system. Apart from the general design of a road tunnel, different technological safety systems can contribute to increased safety. There is, however, no agreed methodology on how to evaluate such systems prior to their design and installation. In this paper, it is recommended that the time required to detect a fire and warn people about it in the tunnel be used as a quality criterion since it has a direct effect on the probability of saving lives. In their previous paper, the authors proposed a fuzzy system called SAFECALC for effectively evaluating fire sensors and warning systems in tunnels, even in the early design phase. The biggest challenge in designing a fuzzy system is the original identification and calibration of such a system. For that reason, this paper focuses on the identification stage and, using the example of a linear fire sensor, it suggests a new methodology for performing such early level calibration. This methodology consists of several steps and, after the original design of the system, it uses inputs provided by experts in the field (via surveys and brainstorming) for fine tuning of the system. A physical model is used to simulate the propagation of a fire in a tunnel. The results of such the process are then evaluated on a real world case study from Lochkov tunnel near the city of Prague.

2017, Transportation Research Procedia, Amsterodam, Elsevier), p. 690-694), ISSN 2352-1465

The paper discusses the Russian experience of standardization in the field of sattelite navigation and ITS for motor vehicles. Work on standardization of technical committees of the Federal Agency on Technical Regulating abd Metrology in these fields is describes. Directions of work on harmonization of standards with international standards of ISO and CEN are shown. Experience of the Czech Republic on standardization within CEN and ISO is describes.

2017, Transportation Research Procedia, Amsterodam, Elsevier), p. 468-473), ISSN 2352-1465

The article describes the potential for capacity increase of a highway section with use of intelligent transport systems. The implemetation results in significant reduction of congestion and accident rate decrease on a highway. It is referring to the first linear control project in the Czech Republic implemented on the automobile ring road around Prague.

2017

Zpráva popisuje využití globálního modelu města, který byl vytvořen v jiných částech projektu, pro kvantitativní hodnocení kvality dopravy nad sítí 108 strategických detektorů. Pro získání údajů o změnách v kvalitě dopravy jsou dopravní parametry vyhodnoceny z několika týdnů před a po otevření TKB. Nad všemi detektory je zavedena kategorizace kvality dopravy, která je transformována do spotřeby pohonných hmot a vyhodnocení délek kolon. Navržené postupy umožňují v budoucnosti hodnotit cenu za přepravu nad sítí detektorů v reálném čase.

2017, 2017 Smart Cities Symposium Prague (SCSP) - IEEE PROCEEDINGS, New York, IEEE Press), ISBN 978-1-5386-3825-5

One of the basic ideas in the field of smart cities is inter-connectivity. Proposed solutions must put together solutions from different fields (sensors, transportation, economy, legislation, energy, IT and many others) and integrate them in order to serve the citizens needs and to ensure sustainability. Additionally this is not done once by buying certain technological tools, but it must be an ongoing process. Thus, not only technological view, but also social aspects must be integrated into services aiming on improvement of the quality of life and sustainability. This is in general a very difficult task, not addressed well by existing methodologies or real world projects. In this paper, we propose a solution to this problem. First, we propose an alternate way of demonstrating the expected outcome of a solution for smart cities. It aims at addressing scenarios from the perspective of the end users rather than ”just” providing an overview of technology and its capabilities as it is mainly done in the technological companies serving as a solution provider. While this is a small change, it has big effect from the customer (municipality) perspective as they can better support the effects on the end users. Second, this paper demonstrates SMACEF - SMArt City Evaluation Framework. This is a modeling tool suitable for evaluation of Smart City Initiatives. On an example of an important square (Charles Square) in Prague, the capital city of the Czech republic, certain buildings blocks, and their interconnections and the possible effects are discussed.

2017, TRANSCOM 2017, 12th International Scientific Conference Of Young Scientists On Sustainable, Modern and Safe Transport, Linz, Elsevier BV), p. 154-159), ISSN 1877-7058

The paper attempts to explain the impacts of large transport structures on the traffic quality and urban environment, in terms of the sustainability of these structures in the long term decades. Such effects can be expressed e.g. via travel time and speed, the length of congestions and time delays, number of stoppings, fuel consumption, location and amount of pollutants produced. The rating is based on the application of mathematical models working with data measured throughout the city, using strategic detectors and floating cars, or test drives. One of the models is the estimation of fuel overconsumption due to reduced travel speed e.g. in congestions, as well as a model determining the delay costs due to traffic situation. Models and measurement data enable to compare the situation before the construction and after implementation of the structures. The method is demonstrated in the case of the Blanka tunnel complex on City Ring Road, which was opened in September 2015.

2017, TRANSCOM 2017, 12th International Scientific Conference Of Young Scientists On Sustainable, Modern and Safe Transport, Linz, Elsevier BV), p. 336-341), ISSN 1877-7058

In this paper, a pragmatic and goal oriented system for risk analysis in road tunnels is described. It is particularly focusing on mortality risks in case of a road tunnel accident. It is a deterministic approach combining three major components: a) vehicle distribution in a tunnel; b) smoke propagation in case of a fire; and c) people evacuation (escape) component. The major improvement of this approach is in capturing the knowledge often provided only by experts into a robust and pragmatic system available to all decision makers. This is achieved through a large number of scenarios combining different configurations of road tunnels (e.g. different number of lanes, different speed limits) and the travel demand (e.g. different structure of the flow, different volumes of traffic) which were prepared and evaluated through microscopic traffic simulation. The resulting scenarios with the information about the number of vehicles in different tunnel sections were obtained. The results describe most of the existing tunnels and situations and can be used universally. Similarly, the people evacuation component can be evaluated in a general form. The results can be manually updated to suit any particular road tunnel which can differ for example by the availability or quality of warning and information systems. The remaining task is to create a physical model of the real tunnel and to model the smoke and fire propagation. All these components were combined into the CAPITA software that was developed as a part of the research project HADES (supported by the Technology Agency of the Czech Republic). The CAPITA software is presented in the last chapter of this paper. The scenarios available off-line are in fact a knowledge base available to experts as well as decision makers and lead to a higher level of comprehension of the developments in case of fire and significantly speed up preparation of a risk analysis.

2017, Dopravná infraštruktúra v mestách, Žilina, Žilinská univerzita v Žiline), p. 1-238), ISBN 978-80-554-1370-9

Příspěvek se zabývá odhadem výše ekonomických a ekologických nákladů při nuceném zpomalení nebo zastavení a následném rozjezdu motorového vozidla v městském provozu a nastiňuje možná řešení vedoucí ke snížení těchto nákladů aktivním řízením dopravy. Náklady jsou řešeny z hlediska ztracené kinetické energie vozidla při brzdění, opotřebení jeho součástí, ztráty času posádky a nakonec zvýšené ekologické stopy v prostředí. Energetické náklady jsou odhadovány z účinnosti motoru vozidla, se kterou při rozjezdu přeměňuje energii paliva na kinetickou energii vozidla ztracenou při brzdění, a z výhřevnosti a ceny použitého paliva. Náklady plynoucí z opotřebení součástí vozidla jsou odhadovány z jejich průměrné uváděné životnosti. Ekonomické ztráty způsobené časovou prodlevou v dopravní kongesci jsou odhadovány z průměrného HDP na osobu a čas. Závěrem jsou výsledky aplikovány na konkrétní dopravní situaci v Praze.

2017

Výzkumná zpráva popisuje využití plovoucích vozidel pro zjišťování parametrů dopravního proudu. Plovoucí vozidlo je vybaveno pozičním systémem a zaznamenává detailní charakter jízdy. Plovoucí vozidla opakovaně jezdila tunelové trasy Městského okruhu a alternativní povrchové trasy. Úspory za kvalitnější jízdu v podzemí jsou vyčísleny ve finančním ekvivalentu.