It is understandable that any measure affecting the productivityof road commercial vehicles is faced with opposition bythe holders and operators oftransp011 companies. This oppositionis so much the greater as much as its preparation and presentationhave been insufficient. The opinion that ecologicalmeasures have a negative impact on the productivity of roadcommercial vehicles is quite widespread: however, laying sucha great stress on that opinion is rather exaggerated. In the courseof introducing ecological measures, a fall in productivity occurs,as a rule, which applies to the time required for the transportcompanies to adapt to it. The duration of the adaptationstage depends on the type of measure and the viability of thecompanies. If the adaptation of entetprises is integral and efficient,the original productivity will be swpassed after the initialfall.

Valorisation of tourist potentials as a guideline for theachievement of strategic determinants of Croatia 's tourism isone of the main determinants of the economic system ofCroatia for the period of upcoming years. Realisation of this determinantis not possible without the implementation of a longterm transport policy and a policy for financing the constructionand maintenance of traffic infrastructure facilities, alongwith other already mentioned factors which exist within theframework of social and economic reality including tourist indusl!y.This indicates that Croatia must take a clear stand with respectto the determining of the traffic infrastructure constructionand maintenance strategy, as the main precondition realisingthe strategic determinants ofCroatian tourism.The authors stmt from the basic conditions of determiningthe strategy traffic infrastructure facilities construction andmaintenance in the function of attaining already set developmentstrategies ofCroatia's tourism. Synchronisation as a pa1tof the process of realisation is possible if it is possible to determinethe feasibility and capability of those responsible for therealisation of the strategy and development of traffic infrastructureand tourist indus!ly. If it is not realised on the level of itsfeasibility, then the only thing we get is one more declarativedocument in the field of economic activity.

Taking advantage of GSM's elaborated mobility managementand its intemational roaming capability, the IntemationalUnion of European Railroad Operators (UJC) has decidedto build a supra-national rail radio network based on enhancedGSM technology.In this pape1; some implemmtation aspects specific to railroadradio environment resulting from the effects of vehiclespeed - in particular Doppler shift - are discussed, and an'off-line' algorithm for the traffic handover is proposed, whichoffers bel/er radio link reliability and less critical timing constraintsthan conventional handover schemes. More reliablehandover is of vital significance in the case of high-speed trainssince the radio link is supposed to cany the automatic controlsignals (ATC), too.

The paper analyses the problem of equipping the roads withinformation and communication infrastructure, for whichthere are no national standards in Croatia yet, so that everythingis left to the skills and experience of the designer. In orderto solve this problem, the paper suggests standards and proceduresfor defining the information and communication equipmentfor the roads.

Computer resources represent a significant factor in the developmentof a society. Their distribution to users' locationsand direct connections through telecommunication systemssubstantially increase their significance and role.Modem telecommunication systems are integral systemsfor voice and data transmission. This paper studies data transferfrom the technical, technological and organisational aspect.Due to the wide scope of the topic, only some relevant data arementioned that dete1mine the characteristics of certain datatransfer systems.

In this article the technical description of the Ground ProximityWaming System (GPWS) is presented in order to considersome of the flying safety factors in commercial aviation,as well as the aspects of interaction between the pilot and thesystem itself during the flight. Since it has been confirmed inpractice that the installation and utilisation of GPWS in aircraftsignificantly reduces the hazards caused by the ControlledFlight Into Ten·ain (CFIT) further development of GPWSequipment presents one of the most important steps in preventingthe ultimate consequences of such aircraft disasters.

Recycling means re-introducing waste material into theproduction process, as addition to primary resources. The useof waste as secondary raw material is economically justified. Byusing old material not only primary raw material is saved, butenergy as well.The paper presents the most frequent materials, the ways inwhich they are collected, and subsequent classification. Thesorting procedures have been mentioned, with throughput capacityan imp01tant parameter expressed in tonnes per hour.The higher the throughput capacity, the better the effect of sorting.

The development of combined transport is highly requiredby the European countries. The pressure, both administrativeand economic, is growing continuously for the use of railway asthe ecologically most suitable land carrier. Considering the protectionof roads, ecological, political and other reasons,Croatia will have to define her policy toward the 'Piggyback'transport in transit (mainly through conidors X and Vb). No efficientintegration into the European system of combined transportcan be expected without the necessa1y stimulating measuresby the government and without a clearly defined transportpolicy.