The presented material on the informatization of the railways operation process discusses its requirement (or necessity) of defining logical technical and technological whose lending themselves to informization. Besides, the suggested proposal is aimed at the resolution of the basic issues of management and control of a company by precisely delineating or separating the operational from the tactical and strategic management and administration. A special review is dedicated to the information science aspect end completion of timetables. In the proposal of the subject solution a re-assignment has been completed of the existing institution of the department in charge of time-tables which in addition to the annual operation schedules have to issue daily schedules thus relieving the work load of the operational (executive) department, precisely defining the work plans for the work period, i.e. work situations. The proposed approach to the informatization is an unavoidable requirement i.e. prerequisite for the integration Jo the railways into the European demand and trends of future development and advancement improvement of operations.

Increased cares for clean environment and limited sources of energy have inevitably resulted in many laws to be passed. This paper deals with some important aspects of subjects laws treating motor exhaust fuzzes and fuel consumption. The expected effects of these laws as well as possible development trends in designing motor vehicles and their engines have been presented.

Digitalization of telecommunications systems is currently in progress. In the light of the fact that the transmission systems make one of the fundamental parts of the system, their capacities are important. This year a new generation of digital transmission systems with up to this point of time the highest rate of 2,5 Hb it/sec has been introduces. The paper discusses the features and possibilities of new systems and their integration into the strategy of telecommunications system digitalization.

The paper deals with the composition and quantities of waste tires of motor vehicles and possibilities of their utilization as possible potential secondary raw materials. The possible quantities available in the world, in the territory of former Yugoslavia, and the city of Zagreb have been reviewed. The possible available quantities of waste tires (pneumatics) in the year 1991 are as follows: in the world this comes to l. 7 x JO pieces of which 84% is still on automobiles, in former Yugoslavia it comes to 9.637.466 pieces or 267.049 tons, and in Zagreb it comes to 862.780 pieces or 18.635 tons while only as /itl/e as less than JO% is collected. It has been established that radial/ tires on automobiles on the roads of Croatia are used up on covered 50.000 kilometers of journey, 8,2% of radial-ply tn1ck tires after 60.000 kilometers 15% and cross-ply 17.1%. Out of a number of methods of utilization of waste rubber pneumatics the environmental and economic highest advantage rests in recycling and processing in cryogen procedure into rubber powder (recycler).

This paper deals with the emissions of carbon dioxide from motor vehicles as an important exhaust gas in the process of building up the greenhouse effect. The discussion covers al/levels of energy con versions -from the primary energy sources to the completion of useful transport by motor vehicles. In this different primary forms of energy are taken into account: appropriate conversion methods for obtaining the motor fuels, different types of fuels, and different structures of engines in the vehicles. The corresponding emissions of carbon monoxide is translated into the unit of transport output i.e. the coefficient is determined of the emission of carbon dioxide as a relevant indicator of the influence of individual elements in the entire chain of con versions in the emission of carbon dioxide.

This paper deals with the specific aspects of liner bus traffic reviewed based upon the information provided by the Main Zagreb Bus Station. A couple of recommendations have been given for the aspired-to improvement of transit passenger transport transit bus traffic and international transit traffic by methods of transport projections of volumes and flows.

The paper deals with the elements of ergonomics with reference to computer systems. The issue refers to the accommodation of working environment to the man i.e. the adjustment of conditions and equipment to the needs and requirements of workers. The analysis covers as follows: office furniture, equipment designing, lighting, noise level, temperature values, and humidity and office medical care information.

The paper deals with the system approach to the analysis of transport systems by means of models. The elaborated approach has been applied in the analysis by means of attend ant or service models or system often used as the only possible ones for studying designing and maintenance of transport processes at all levels.

The Republic of Croatia is to a major degree interested in an accelerated modernization of the Adriatic-Danube Basin (Rijeka-Central European Countries) traffic corridor, to meet both its own requirements and the requirements o[ Central European countries which do not have a direct exit to the sea but have major volumes of transit freight transported by sea. The Rijeka-Zagreb railway line nowadays is not any limitation factor in either passenger or freight transport however the subject capacities should be maximum extended while taking account of all engineering and technological and management measures. The operation of the railway line should be made synchronous with the operation of the Rijeka railway junction, and port capacities (also calling for modernization) and finally with the facilities of the Zagreb Marshaling Yard. Geographic and traffic-aspersed advantages of Zagreb, in particular its significance in the corridor of Central Europe sets the requirement for the construction of a container terminal and goods collection and distribution center in Zagreb as major link on the Rijeka-Danube basin freight flows route.

This paper deals with the review of the existing conditions of platforms in the area of integration of the railways into the system of urban and suburban passenger transport in the City of Zagreb, and sets forth the recommendations of engineering (technical) resolutions for the construction of new platforms.

Strategic telecommunication development direction in Croatia has to be expected in three segments. The first relates to the achievement of the appropriate subscriber density of the basic telecommunication service – telephony (GTP), the second is in the modernization and application of new technologies of the telecommunication network (IDN, ISDN), and the third refers to the introduction of the wide range of new telecommunication services. Review and systematization of the telecommunication services is the main topics of the paper. A group of voice services and possibilities and non-voice services have been analyzed. In the paper there has also been discussed the problem of service integration from the exploitation viewpoint, technical and technological solutions as well as the commercial attractiveness. In it there has been given the review of the activities and the level of introduction of new services in HPT.

The authors set forth the criterion (i.e. the standard) which makes it possible to select one out of nine two-parameter models, i. e. empiric equations. This refers us to the very simple models which are rather frequently used in different applications including all aspects of traffic. Their utilization has been illustrated by examples.

This paper discusses the results of research in three different telecommunications system planning and management segments: link-up of the system control center and the outlying computer, estimate of the control center reliability and development of the algorhytm for optimization in the subscriber region. In addition the paper provides a parallel review and comparison of experiences related to the method of research in all three mentioned segments.

The concentration of carbon monoxide in motor vehicle engine exhaust emissions is rather important because it has the highest impact upon its toxic aspects. The emission of CO into the atmosphere from motor vehicle exhaust reaches the figure of 65%. The elements of exploitation on one side are the interchangeable systems of operation and on the other the change of the original drive features. The paper deals with the impacts of speed at different levels of transmission, richness of mixture, air temperature, height above sea level and road incline upon the concentration of CO.

Specific aspects of air transport as a unique engineering, technological, management and economic complex dynamic system in particular its specific engineering and technological features have conditioned a specific resolution of the requirements regarding the speed and efficiency of completion of the transport process and the requirements regarding the reduction of costs by introduction of all modern transport technologies characterized with inclusion of technical means and devices between the transportation means and freight for purposes of introduction of unit loads (freight) and concentration of freight (pallets and containers. Palletization and containerization of freight transported by aircraft have been accommodated lo technical and technological characteristics of transportation means in air transport so that consequently the circulation of pallets and containers used in air transport is mostly completed inside the system of air transport.

There exists no uniform definition of the terms of integrated, multi-modal and combined transport. The paper provides a review and a sort of delineation of the terms of integrated, multi-modal and combined transport.

Piggy back technology of freight rail transport has particularly been invigorated .by the second world energy crisis of 1978. For purposes of relieving individual road routes, better utilization of rail infrastructure, reasons of environmental protection, lower costs, higher speed and safety of transport, the EEC supports financially the development of this aspect of transport technology. This paper deals with the existing organization/management of piggy-back transport in Europe with particular reference to the indices of efficiency of the German Society for Transport of Road Vehicles by Rail entitled 'Kombiverkehr A. G.'. Through identification of the forwarding agent as the organizer of shipment and delivery of goods by this technology the author refers us to the indispensability of this legal entity which as an entrepreneur acts on behalf of the business organization on completion of transport to satisfaction of the party providing and the party using this type of transport service.

This paper deals with a major function of the road in populated areas with particular reference to the measures taken on abatement of traffic flows. Considering the fact that major part of the area designed for traffic in populated areas has been used for purposes of road traffic to disadvantage of pedestrians and cyclists, it is necessary to initiate activities on purposes of structuring of the road area and this by measures of abatement of traffic flows with the basic objective of humanization of traffic i.e. harmonization of community life and traffic in the urban area. This paper deals with some examples of listed measures with low, r:cdiwn and high funding requirements.

Traffic infrastructure makes an integral part of the traffic and economic system of a country. This fact sets for those who create the policy of investment into the facilities of traffic infrastructure the task to have it based upon scientific nations and a coordinated activity of all segments of economy. This paper deals with the impacts of investment activities in the area of traffic infrastructure upon a congruent development of the economic system. The accent has been placed upon respective investment activity whose decisions are based upon economy-aspected criteria i.e. upon a more expressed import of scientific methods and application of scientifically determined and verified methods for this type of investment activity.

This paper deals with calibration (structuring) of a stochastic disaggregate binary model of road use selection: the motorway of a parallel road option. The variables of the model are the length of the road used and differences in the time of journey on the motorway and parallel road. Considering the road user/Es manner of assessment of time savings, a time variable has been structured in two ways: in the shape of 'differences' (time of journey on the motorway- time of journey on the parallel road) i. e. the quotient (time of journey on the motorway /time of journey on the parallel road).

Traffic signs refer to a specific technique of controlling some human relations, conditions and behavior in traffic. In other spheres of community life, as to a degree in traffic, these relationships, conditions and behavior patterns are being regulated by legal rules (standards) being communicated descriptively. Therefore it is important to define the legal nature of traffic signs, their impacts as referring to the obligations and liabilities, as well as the differences and specific aspects with reference to traditional conventional legal rules and standards.

The development of the automobile industry has invigorated the development and advancement of the tire manufacturers. Considering the fact that the tire is a major factor of traffic safety it should be secured proper maintenance and inspection.

New transport technologies can be grouped with reference to their engineering and technological characteristics into different systems, sub-systems and segments. However, in this process of grouping i.e. defining the modalities and terms it is indispensable to reach a unique standardized definition in domestic and international relations in order to avoid diverse terms for one and the same sub-system. Thus in practice we meet different terms for new transport technologies: integrated transport, combined transport, means of modern transport technologies, integrated transport systems, new transport technologies, etc. Up to this point in time only multi-modal transport (MT) has been defined from engineering/technological, management and legal aspects by acceptance of the Convention on Multi-modal transport on the part of the United Nations (UN), UNCTAD, in the year 1980. As other modern transport systems have not been defined so far or standardized on the model of the MT the author in this paper advocates a uniform and unique name of Integrated Transport Systems for the following three basic systems: Integrated Transport, Multi-modal Transport, Combined Transport, while each and every of them keeps its sub-systems and segments as presented in Figure l . The definition has been dealt with through synthesis and analysis considering engineering and technological characteristics, their compatibility, incompatibility and other relevant factors.

The author deals in this paper with a review of reconstruction of intermediate stations for accommodation to transit speeds of 160 km/hr on the double track section of the Beograd-Zagreb rail on the Vinkovci-Novska route section with reference to the overall issue regarding the introduction of the speeds of 160 km/hr.

The fatigue of train drivers has been dealt with both from theoretical and practical standpoint in conjunction with respective examples from the practice. The appearance of fatigue has been viewed as a result of changes detected in the blood and urine, higher pulse rate, decreased ventilation of the respiratory organs etc. Owing to these changes the driver’s working capacity i. e. actual performance is reduced, he becomes sleepy without being able to resist it, so the driver falls asleep on his working post in the drive rs 's cab. To illustrate the situation the author has reviewed the severe rail accident that happened at the Zagreb Main Station in 1974. Making the driver fit for his further operation is possible only through and after an appropriate rest which refers in the first place to repose in quiet and other conditions indispensable for a sound and comfortable sleep. After such adequate rest all bodily and working functions of the driver grant a good and safety-aspected operation of the locomotive.

This paper deals with the defining of the diagnosing parameter as the moment of the piston stroke on the cylinder as expressed by the angle of the crankshaft. The established diagnosing parameter has been examined. This property is indispensable in the light of the fact that if missing the selected diagnosing parameter cannot be applied with necessary reliability for cylinder wear diagnosing. The stability of the diagnosing parameter has been verified in experiments for different values of cylinder wear.

River transport in our country, and particularly on the territory of the Republic of Croatia, creates major possibilities for services required for industries in both domestic and international transport. Considering the fact that this aspect of transport is one of the least expensive in the general transport system it should be as soon as possible reinstated an made adequate from the engineering and technological standpoint to realistically take its due place in the transport industry. Drawing a comparison of the construction of the Rhine-Main- Danube Canal to Cherna Voda-Constance and the development of other Adriatic- Danube Basin traffic routes to our actual requirements and reflections upon the condition of development of our waterways, the question is raised on the future of development of our river shipping i. e. construction of the Šamac- Vukovar canal and opening of the Sava river for navigation all the way to Zagreb.

This paper deals with major technical and utilization properties of the new system of wireless telephone communication - the TELEPO/NT. The system introduces a modified tapeless telephone technique of increase range and thus the increased mobility of the parties.

This paper deals with the definition and review of financial postal services group in the period of 1981-1989 . Based upon the review the author draws his conclusions on the existing clearly pronounced divergence in the tendencies of individual types of services, involving their division in two opposite development trends. Payment operations and banking services for different business banks show high rates of annual increase while at the same time postal money orders and banking services of the Postal Saving Bank mark steady decrease in the years of the observed period. However, viewed as a group of services (a segment) they have marked a high average annual rate of increase of6.2% for the territory of the Yugoslav Posts and 5. 5 % for the territory of the Croatian Posts due to a dominant share of the former of 93% for Yugoslavia and 95% for Croatia as compared to the latter.

This paper deals with the analysis of ergonomic aspects of traffic safety. l n this light, the following aspects have been considered: psycho-physiological, structural/system/ technical, engineering and teaching aspects. The issues raised, the principles and methods of ergonomic problems of traffic safety, through individual aspects being mutually integrated, can usefully serve the organizers and immediate operators in the process and endeavors of raising traffic safety to a more advanced level.

Telecommunication facilities, in particular the numbers of main telephone lines in the world have listed a very even and balanced development since the very beginning. For 56 nations with the highest number of main telephone lines the author provides the review of respective capacities, distribution per l OO inhabitants, and respective growth rate with the average annual growth rate in the period between 1987 and 1988. Economic comparison bas been drawn to the gross national product and respective correlation function bas been provided of the distribution of main lines per 100 inhabitants and gross national product per capita. The countries covered in this review account for over 97% of world telephone communication capacities.

As a result of an extensive research, different models of review and follow-up/monitoring of transport demand and freight flows have been obtained. Transport demand is either related either to the origin or destination while freight flows may be incoming and outgoing (inward and outward-bound) in (to) a given location or facility, as for instance a container terminal. Furthermore, simulation and mathematical models of monitoring and review of distribution channels and transport flows optimization have been dealt with in this paper.

This paper deals with the proposed model for determining the optimal number of parking places following the conditions and requirements of high standard of provision of services to the users and positive economic effects of car parking operations. The characteristics of car parking operations have been obtained through simulation on the model by varying the input parameters as the intensity of the input flow, parking times, number of parking places, etc. Checking of the results obtained has been completed by application of economic methods.

This paper deals with the drugs which affect the psychophysical characteristic of man, commonly known as trigonic drugs. In the spirit of our regulations trigonic fall into the category of those drugs ultimately prohibited to motorists and machine operators and the category of those drugs known for possible effects upon the psychophysical characteristics of a motorist. It has been suggested to the motorists to study carefully respective instructions for use i.e. administration of these drugs and get familiar with the effects and side-effects of the medicine. Trigonics have been indicated to account for some 12% of all road traffic accidents reported causes.

Piggy-back transport has been up to this point of time the most efficient segment of freight transport by means of modern technologies combining rail and road aspects. This modern transport mode as compared to traditional transport offers a variety of advantages in the shape of: economical consumption of petroleum products, higher rail and road fleet utilization coefficient, longer road vehicle(s) operation life, reduced wear of carriageways, higher-quality and safer transportation, reduced transportation costs, environmental concerns, etc. In our country in 1981 and 1982 respectively a piggy-back train was 6perating on the Jesenice- Ljubljana and Zagreb-Belgrade-Gevgelia routes to be cancelled subsequently: such a train is presently operating only on the Jesenice-Ljubljana- Koper route. In the light of the above listed advantages it will absolutely be necessary to re-introduce this train on the one-time routes, as well as on the Zagreb-Rijeka and ZagrebSplit and Zagreb-Osijek- Vinkovci routes. Measures on the prevention of adverse environmental effects of traffic and legislative, management, engineering and technological, educational and other effects {as dealt with in this paper) should necessarily be updated, modernized and intensified in their implementation. This will yield the expected and aspired-to effects of environmental protection and advanced traffic safety.

Traffic infrastructure as an inseparable segment of community and business life takes an important position in the sphere of a harmonious development of all segments of the social reproduction process. This means that a harmonious development in the area of a rational and economic investment activity including traffic infrastructure facilities must inevitably take heed of the effects of the external economy and external diseconomy. In this the traffic infrastructure facilities develop into the elements of harmonious relationships in the process of the investment activity, which must not and absolutely cannot be unilateral. The complex aspect of viewing both positive and negative effects is a distinctive quality of each and every rational investment activity, because it is an accepted fact that there exists no such activity which yields only positive effects. These investment activities oriented towards traffic infrastructure facilities in the community and business systems must arise from more complex reviews and verified methods for the final effects to incorporate all the elements of a harmonious relationship of positive and negative effects of a concrete investment operation. The paper deals with respective effects and indispensable coordination of external economy and external diseconomy, which has been regarded in the up-to-date processes of the investment activity as only a marginal problem, present yet not worth deeper reviewing. .By gradual dehumanization of the environment coming as a result of an uneconomical and inadequately controlled investment activity i.e. advance exploitation of the resources of future generations, we face a problem which no longer has a restricted effect but has already metastasized into all cells of life and has been faking daily its gigantic toll.

This paper deals with the method which makes it possible to complete an assessment of the harmful exhaust emission level of the Otto engine in different modes of operation. Thus the paper specifically reviews: idling, stationary loads, acceleration, and deceleration. The authors discuss the impact of input values in the process of assessment upon the output values. In the process, respective concentration as well as the total volume of toxic components in a given period ·have been established. The assessment is based upon a complete estimate (computation) of a cycle in the engine cylinder while the load is selected from the system of the Europe-test. The results obtained have been verified in an experiment.

The author discusses the process of rationalization by introduction of the ŽEPK management and information system in the Rail Transport Company of Zagreb and reviews its technical and technological and economic effects. Then the author provides the assessment of recommendations with reference to the fact that the very process as a segment cannot yield the wanted effects on the entire system unless synchronized on the entire network of Yugoslav Railways. This brings us to the fact that our only prospective refers to the synchronous activities and integration into the European rail system as a partner in its own right. The path leading to the materialization of this as compared to the current state of affairs appears to be a difficult one however any failure to integrate leads us into an unavoidable traffic isolation to inevitably exhibit adverse influence onto our entire social/ economic development in the future.

This paper provides a review of legal provisions effective in Europe and the states aimed at the reduction of harmful diesel exhaust emissions. Resolutions of the problems resulting from respective reduction of harmful emissions fall into three groups: improvements of the structure and technology of the engine, utilization of higher-quality fuels and lubricants and treatment of gases upon exhaust from the cylinder.

Connectionism represents a possible approach to the resolution of the issues of insufficiently described traffic systems. The system for keeping records on transport capacities of the fleet has been structured by a system of processing units. The output of an individual unit has been determined by the number of products of multiplication of the incidence of input attributes and the strength of their association links. The proposed model has been implemented for vehicles of the fleet described with eight groups (classes) of information. Verification of the application of the connectionism model within the scope of expedite monitoring (follow-up} of performance of transportation means has been completed in an effort of searching for the characteristics of the vehicle according to the data from the records (register) on individual vehicles, identification of the vehicle according to an insufficient description of its characteristics and in cases of spontaneous generalization of characteristics of a vehicle.

Some relevant studies show that telecommunications and respective system of services (utilization) possess the characteristics of a natural monopoly, further confirmed by the established effects of the economic scale of 1.04-1.16. Nevertheless the effects of liberalization and privatization and introduction of competition in a number of countries are positive and filter through to even the level of local network and lines. Within this scope (from the aspect business administration of operations) the thesis has been developed that the possible efficient solution refers to an asymmetrical aspect of competition with competitors’ access permissions 011 the basis of concessions and compensations. Respective concept can find its justification in the case of a low level (smaller volumes) of telecommunications system development - the system of basic services - while for the telematic services an open competition is desirable.

This paper deals with certain possibilities of telecommunications service improvement in rural areas with particular reference to social and economic advantages for the inhabitants. Based on the derived relation for respective telephone demand (the relation between the incidence of calls and the distance of telephone locations) it is possible to assess the economic benefits by means of a simulated model of spatial distribution of telephone locations. In relation to the idea of the telecommunications traffic volume and the surplus number of users (the relation of benefits and costs to the user) respective economic benefit reveals and reflects itself in the reduction of the distance travelled by a telephone user in a rural area.

U radu se daje opći prikaz nove PTT usluge- radiopoziva (radio-paging}, koja se realizira u suradnji s RTV. Prvo se opisuje konfiguracija sustava radiopoziva, te se daje pregled osnovnih značajki njegovih glavnih dijelova. Zatim se analizira razvoj radiopoziva u svijetu i u nas. Na kraju se razmatra perspektiva ove usluge u odnosu na mobilnu telefoniju, te pretpostavlja njen mogući razvoj.