Abstract

The goal of the study was to investigate if the drivers behave in the same way when they are driving a motorcycle or a car. For this purpose, the Motorcycle Rider Behaviour Questionnaire and Driver Behaviour Questionnaire were conducted among the same drivers population. Items of questionnaires were used to develop a structural equation model with two factors, one for the motorcyclist's behaviour, and the other for the car driver's behaviour. Exploratory and confirmatory factor analyses were also applied in this study. Results revealed a certain difference in driving behaviour. The principal reason lies probably in mental consciousness that the risk-taking driving of a motorbike can result in much more catastrophic consequences than when driving a car. The drivers also pointed out this kind of thinking and the developed model has statistically confirmed the behavioural differences. The implications of these findings are also argued in relation to the validation of the appropriateness of the existing traffic regulations. Glavni namen raziskave je preučevanje morebitnih vedenjskih razlik motoristov pri vožnji z motornim kolesom ali avtomobilom. V ta namen je izvedena anketa v obliki dveh vprašalnikov med isto populacijo motoristov. Prvi vprašalnik zrcali motoristične vedenjske, drugi pa avtomobilistične vedenjske vzorce. Na osnovi zbranih podatkov ankete je razvit model strukturnih enačb z dvema faktorjema, eden se nanaša na vedenjske lastnosti vožnje z motorjem, drugi pa na vedenjske lastnosti vožnje z avtom. V procesu razvoja modela sta uporabljeni tudi eksploratorna in potrditvena faktorska analiza. Rezultati kažejo, da dejansko obstajajo določene razlike v voznem obnašanju. Glavni razlog za to je verjetno v mentalnem zavedanju motoristov, da rizična vožnja z motorjem lahko vodi do mnogo hujših posledic v primerjavi z vožnjo z avtom. Motoristi namreč posebej izpostavijo tovrstno dojemanje razlik pri vožnji z motorjem ali avtom, kar naš model tudi statistično potrdi. Implikacije teh ugotovitev so soočene z morebitno neustreznostjo obstoječe prometne zakonodaje.

Abstract

Background Surging acceptance of adaptive cruise control (ACC) across the globe is further escalating concerns over its energy impact. Two questions have directed much of this project: how to distinguish ACC driving behaviour from that of the human driver and how to identify the ACC energy impact. As opposed to simulations or test-track experiments as described in previous studies, this work is unique because it was performed in real-world car-following scenarios with a variety of vehicle specifications, propulsion systems, drivers, and road and traffic conditions. Methods Tractive energy consumption serves as the energy impact indicator, ruling out the effect of the propulsion system. To further isolate the driving behaviour as the only possible contributor to tractive energy differences, two techniques are offered to normalize heterogeneous vehicle specifications and road and traffic conditions. Finally, ACC driving behaviour is compared with that of the human driver from transient and statistical perspectives. Its impact on tractive energy consumption is then evaluated from individual and platoon perspectives. Results Our data suggest that unlike human drivers, ACC followers lead to string instability. Their inability to absorb the speed overshoots may partly be explained by their high responsiveness from a control theory perspective. Statistical results might imply the followers in the automated or mixed traffic flow generally perform worse in reproducing the driving style of the preceding vehicle. On the individual level, ACC followers have tractive energy consumption 2.7 – 20.5 % higher than those of human counterparts. On the platoon level, the tractive energy values of ACC followers tend to consecutively increase (11.2 – 17.3 %). Conclusions In general, therefore, ACC impacts negatively on tractive energy efficiency. This research provides a feasible path for evaluating the energy impact of ACC in real-world applications. Moreover, the findings have significant implications for ACC safety design when handling the stability-responsiveness trade-off. Document type: Article

Abstract

In-vehicle systems that assist the driver with his driving task are developed and introduced to the market at increasing rate. Drivers may be supported during congested traffic conditions by a so-called Congestion Assistant consisting of a mix of informing, assisting and controlling functions. This paper describes the impacts of the Congestion Assistant on the driver in terms of driving behaviour and acceptance. Thirty-seven participants took part in a driving simulator study. The observed driving behaviour showed promising improvements in traffic safety when approaching the traffic jam. Moreover, positive effects of the system on traffic efficiency can be expected in the jam. The participants stated to appreciate the Congestion Assistant, although not all functions were equally rated. To increase the performance and acceptance of the total system, some refinements were suggested. Keywords: Congestion Assistant; Driving simulator; Integrated system; Driving behaviour; Acceptance