A total of 25 anthropological measures important for the engine driver's cab design were taken from a sample of 51 male engine drivers from all parts of Croatia, out of which 5 and 95 percentiles along with central 90 % were determined. According to scientific findings that body height decreases with age, subjects were divided by age into four groups. Calculated arithmetic mean and harmonic mean of ratios hi/h for individual anthropological measures hi in relation to the standing height h are the same for all age groups, with minor deviations. The research has been taken whenever it was possible to use body ratios hi/h for the design of driver's cab in new vehicles adapted to the target population of drivers, only by knowing standing height and mass span in the central 90%. For final conclusions the research should be repeated with a larger sample, taking into account amounts of BMI within each age group because of insufficient and unequal number of respondents in age groups.

While operating a locomotive or a railcar the engine drivers are exposed to the action of several simultaneous factors of disturbances from the traffic environment, and therefore their reliability and safety are reduced. The human-determined physical, sensor and cognitive factors are not only the attributes of the engine driver, but also include influences from the traffic environment, due to the interaction in the “engine driver – traffic means – traffic environment” system. Traffic environment is defined in such a way that, among other things, it includes also the working environment of the drivers cab and the recent traffic situation. The action of factors of temporary subjective disturbances and/or permanent psychological and physiological changes, depend not only on the individual endurance of engine drivers, but also significantly on the type of locomotive or railcar operated by the engine driver, as well as on the fact whether the traffic is intended for the transport of passengers and/or freight, or a shunting engine is involved. The ergo-assessment based on a survey of 50 respondents yielded the final results that are almost identical to the results of ergo-assessment obtained during the formation of the methodology of cognitive ergo-assessment on a sample of 31 respondents. In both cases the surveyed respondents were engine drivers who in practice operate all types of locomotives and railcars, who have acquired engine driver secondary school qualifications and have passed vocational testing for all types of locomotives and railcars. Systemic ergo-assessment of the intensity of the overall psychophysical effort is possible by introducing the index of importance which is used in case of all engine drivers to integrally and equally recognise also the influence of the percentage of occurrence of a certain factor of subjective disturbance and influence of the average assessment of the subjective disturbance intensity, thus allowing an insight into the structure of a system of simultaneous ergo-assessment factors and isolation of ten dominant ergo-assessment factors. Partial cognitive ergo-assessment and inter-comparison of the intensity of subjective disturbances have indicated the types of locomotives and/or railcar compositions in which the maximum partial intensity of disturbance is due to the following factors regarding the working ambient of the drivers cab: visibility, intensity of the difficulty of operation, and intensity of disturbance of the audible traffic noise. KEY WORDS: traffic environment, cognitive ergo-assessment, dominant factors of subjective disturbances, assessment parameters, safety and reliability

Original scientific paper Frequently used commands on the locomotive or railcar control panel need to be arranged mainly within the normal reach of the arm, using multi-purpose controllers for serving several important and frequently used functions by one hand, whenever possible. From the measured anthropometric measures in the central 90 % from the sufficient and random sample of 50 engine drivers the range of normal and maximal reach of arm has been defined using statistical methods for the entire population in Croatia. The ranges of statistical anthrompometric measures of the engine drivers are the constitutional factors from the group "human factor", and according to Fuller TCI model "task requirement -driver's capability" affect the difficulty of the task during driving. The correlation dependence of lumbar moment Ml on the index of mass BMI has been proven in the hypothetically most unfavourable statistical seating working position, and based on the really measured statistical anthropometric measures. Keywords: anthropometric measures; central 90 %; engine drivers; human factor; normal and maximal reach of arm; task difficultyAntropomjere bitne za dizajn upravljačke ploče u lokomotivi ili motornoj garnituri Izvorni znanstveni članak Često korištene komande na upravljačkoj ploči lokomotive ili motorne garniture potrebno je rasporediti pretežito unutar normalnog dosega ruku, uz korištenje višenamjenskih kontrolera za posluživanje više bitnih i često korištenih funkcija jednom rukom, kada god je to moguće. Iz izmjerenih antropomjera u središnjih 90 % od dovoljnog i slučajnog uzorka od 50 strojovođa statističkim metodama definiran je raspon normalnog i maksimalnog dosega ruku za cijelu populaciju u RH. Rasponi statičkih antropomjera strojovođa su konstitucijski čimbenici iz grupe "ljudskog faktora", a prema Fullerovom TCI modelu "zahtjev zadaće-sposobnost vozača" utječu na težinu zadaće tijekom vožnje. Dokazana je korelacijska ovisnost lumbalnog momenta Ml o indeksu tjelesne mase ITM u hipotetski najnepovoljnijem statičkom sjedećem radnom položaju, a na temelju stvarno izmjerenih statičkih antropomjera.Ključne riječi: antropomjere; ljudski faktor; normalni i maksimalni doseg ruku; središnjih 90 %; strojovođe; težina zadaće

BACKGROUND: Inconsistent findings on coupled illumination, accumulated noise and task complexity effects on cognitive-motor performance asked for a more comprehensive analysis by focusing on performance dynamics. OBJECTIVE: The aim was to investigate the effects of illumination, accumulated noise, and task complexity on several average and non-average temporal indicators. METHODS: The research was designed as a mixed factorial quasi-experiment including 83 students of transport (n = 42) and psychology (n = 41) at the University of Zagreb. Participants were assigned to designated experimental conditions defined by illumination (40, 280, 3400 lx), and accumulated noise (0% and 50% of the daily exposure limit) levels and all performed 2- and 8-choice reaction time tests. RESULTS: The findings showed negative effects of accumulated noise and task complexity on all performance indicators, while the effect of illumination reached significance only for maximal speed. Significant Illumination x Task complexity and Illumination x Accumulated noise effects were obtained for average efficiency, while significant Accumulated noise x Task complexity effect was observed for average efficiency and maximal speed. CONCLUSIONS: Various indicators of performance dynamics were diversely affected by external factors, thereby suggesting the effects’ mechanisms, and accentuating different guidelines for design of workplaces that include these environmental stressors.

Previous studies have shown that the impact of interior aircraft noise on pilot performance was not unambiguous, neither there was any unanimous methodology used for measuring it. Furthermore, the cumulative character of noise was never taken into account. This research proposes a methodology that aims to determine the impact of INTRODUCTIONEvery day's flight tasks performed by pilots require concentration, analytical illation, precise movements, continuous performance, and long-term attention. Such tasks are particularly expressed in the process of flight training since automatic flight control systems on the general aviation aircraft during basic flight training are not in use. The effectiveness of the pilot in performing tasks significantly affects flight efficiency and safety. At the same time, pilot performance is affected by the environmental factors in the cockpit with noise being the most significant one.Human factors in aviation were gradually developed and institutionalized by the end of the 1970s. They denote a term that describes various pilot performance aspects interacting with environmental factors in the aircraft cockpit, while pilot performance means aircraft guidance along with navigation and communication management. The error, which is defined as the action -or lack of action -and which leads pilots to deviate from the institutional or the pilot's intentions or expectations, is important performance viewpoint in aviation. The quality of pilot work has certain significance, not only as the effectiveness, but also as for outcomes such as efficiency and flight safety [1]. McFadden in [2] elaborates on the causes of pilot errors and safety threats in aviation, but does not include the impact of all the working environment factors in the aircraft cockpit. These factors are humidity, temperature, pressure, vibration, and, above all, the noise. Noise impact on pilots requires a sufficient level of noise etiology knowledge in order to reduce the potential negative impact on the efficiency and flight safety through adequate noise reduction procedures. This requirement is more pronounced in cases with a high degree of interaction between the pilot and the aircraft which is particularly distinctive in general aviation aircraft during basic flight training where there is no auto-pilot system in use. Research conducted on the Croatian national carrier pilots showed that flight safety was at least once disturbed by noise in 27.8% and 38.5% of turbofan and turboprop aircraft pilots, respectively [3]. The results were achieved by polling without putting the emphasis on actual effect of noise on pilot performance.The effects of exposure to noise can be physiological and psychological. The physiological effects can be auditory or non-auditory (extra-auditory or JURICA IVOŠEVIĆ, Ph.D. 1