European Transport Research Review

COVID-19 pandemic is a challenge that the world had never encountered in the last 100 years. In order to mitigate its negative effects, governments worldwide took action by prohibiting at first certain activities and in some cases by a countrywide lockdown. Greece was among the countries that were struck by the pandemic. Governmental authorities took action in limiting the spread of the pandemic through a series of countermeasures, which built up to a countrywide lockdown that lasted 42 days. This research aims at identifying the effect of certain socioeconomic factors on the travel behaviour of Greek citizens and at investigating whether any social groups were comparatively less privileged or suffered more from the lockdown. To this end, a dynamic online questionnaire survey on mobility characteristics was designed and distributed to Greek citizens during the lockdown period, which resulted in 1,259 valid responses. Collected data were analysed through descriptive and inferential statistical tests, in order to identify mobility patterns and correlations with certain socioeconomic characteristics. Additionally, a Generalised Linear Model (GLM) was developed in order to examine the potential influence of socioeconomic characteristics to trip frequency before and during the lockdown period. Outcomes indicate a decisive decrease in trip frequencies due to the lockdown. Furthermore, the model’s results indicate significant correlations between gender, income and trip frequencies during the lockdown, something that is not evident in the pre-pandemic era.

This manuscript presents the experimental plan and results of driver trials conducted with a semi-dynamic driving simulator and an equipped research vehicle in real traffic conditions. 12 trainees, 12 novice (driving license less than 1.5 years; 25,000 totally run km by average) and 12 experienced drivers (driving license more than 12 years; 320,000 totally run km and 28583 km only the last year by average) participated in the trials, conducting the same driving sessions in the simulator and on-the-road, consisting of a free driving and a following vehicle scenario in the context of highways, rural and urban roads. Their maximum speed, difference of their average speed from each speed limit and their average lateral deviation in driving simulator and on-the-road were compared. A novel research framework was established for the results analysis dealing with the existence of numerical proximity between the driving simulator and the on-the-road measurements (in the sense of absolute validity), the degree of this proximity and the possibility and the type of the correction that could be applied leading to an acceptable absolute validity. Derived results have shown that several degrees of numerical proximity apply for different combinations of driver behaviour metrics, driver cohorts, driving tasks and road contexts, whereas the type of the driver behaviour metric seems to be the most determining factor for absolute validity existence. Tangible findings consist of transfer algorithms that serve as the basis for redefining warning and intervention thresholds of ADAS but also driver training and assessment schemes based on driving simulators.

The purpose of this systematic literature review is to contribute to the knowledge about barriers to change in urban freight systems and to support managed changes toward more sustainable urban freight systems. This paper is based on a systematic review covering 93 peer-reviewed journal articles. The study was designed to advance earlier research in this area by providing a system perspective on barriers to development in urban freight systems. The theoretical knowledge about these barriers was analyzed and synthesized, the relationships between barriers explored, and the insights developed into a model of understanding of managed change processes in urban freight systems. From a system perspective 11 categories of barriers to change in urban freight systems were identified and characterized. The barriers are, in different ways, related both to each other and to a managed change process for sustainable development of urban freight systems. A model for understanding categories of barriers and their connection to managed change processes in urban freight systems is proposed in this paper. The model consists of three groups of barriers within the process, and two groups in the system context, which should be addressed with different priorities in a managed change process. The study identifies several future research options. Future research could support the development of sustainable urban freight systems by providing insights into change process governance, potentially by combining theory from areas like organization, systems, and networks with the system perspective on urban freight systems. Research on non-European urban freight systems could increase the scholarly insights about contextual impact on barriers and change processes. Future studies could also explore methods to mitigate identified barriers, especially in the areas of cooperation, organization, politics, knowledge, and the first mover disadvantage. Finally, future research should continue to develop the model of the managed change process for urban freight systems and its use in supporting sustainable development of these systems.

This study identifies and compares perceptions of autonomous vehicle (AV) implementation among three Swedish stakeholder groups: Future Users, Urban Planners, and Developers. Semi-structured comparative focus groups were conducted separately with each of the three groups of stakeholders and the transcripts were analysed in broad themes using thematic analysis. Assumptions, hopes, concerns, and direction of development were the main themes that emerged from the analysis. Assumptions included electrification of vehicles, changes in travel demand, and the need for regulations; Hopes included the idea that AVs will contribute to a more accessible and safer transport system; Concerns included overtrust in AV technology, a possible detrimental impact on the city in the form of congestion and higher demand for investments in infrastructure that could outcompete other modes of transport; and Direction of development and their own role, where the need for collaboration between stakeholders and implementation of AVs in connection with society’s needs were emphasised. AVs were seen to lead to both positive and negative consequences depending on implementation and the development of society. The study shows that dialogue between different stakeholders is lacking but it is desired for the inclusive implementation of AVs.

The European Union wishes to develop strategies to increase the number of urban transport passengers over the coming years. Urban transport is the key transport mode for the decrease of congestion, pollution, energy consumption and limitation of land use by transport in cities. Urban areas are the drivers of the European economy. This implication of European authorities rests on the means mobilised in European research projects. These research projects aim at conceiving the common model of the future safe and interchangeable guided transport systems in Europe and highlights the problems related to the harmonisation of the steps of safety certification of such systems. Therefore, the concept of interchangeability ((UGTMS), (MODURBAN)), is important and, it means that system components can be produced from any suppliers and replaced without any substantial change in functionality or performance. It also allows the system to adapt to technology evolutions without significant modifications to its architecture. The main barriers for reaching these objectives are the complexity of the existing systems, the diversity of national legislation and the lack of international standards. The common model of this framework is needed to open the competitive market for urban transport.

This paper outlines a complex simulation model for parallel-hybrid diesel railcars with hydrodynamic power transmission. It contributes to the discussion concerning whether a hydrostatic recuperation system can be an alternative to electric systems using double-layer capacitors or flywheels. The paper focusses on a hybrid system with realistic parameters concerning mass, power, and energy content that should be applicable to both existing and newly built vehicles. A simulation process that is based on the 1-d-multi-domain simulation tool Imagine.Lab AMESim is presented. The simulation comprises a conventional and an alternative drive train as well as the longitudinal dynamics of the vehicle along with the control of the vehicle motion. Energy-efficient driving techniques and timetable restrictions are taken into account when comparing train runs of different drivetrain configurations. Simulations based on real route data for eight different railway lines show a reduction of fuel consumption between 5 and 16 % due to the hydrostatic recuperation of energy. Station spacing and mean line gradients prove to be important line-side factors impacting fuel economy. Hydrostatic recuperation represents a feasible solution for railcars, provided that possible spatial and economic obstacles can be overcome. As the simulation results are promising, further hybrid configurations will be considered for simulation. A comprehensive comparison to models of hybrid diesel railcars using different energy storages is the next step.

Energy Policy is one of the main drivers of Transport Policy. A number of strategies to reduce current energy consumption trends in the transport sector have been designed over the last decades. They include fuel taxes, more efficient technologies and changing travel behavior through demand regulation. But energy market has a high degree of uncertainty and the effectiveness of those policy options should be assessed. A scenario based assessment methodology has been developed in the frame of the EU project STEPS. It provides an integrated view of Energy efficiency, environment, social and competitiveness impacts of the different strategies. It has been applied at European level and to five specific Regions. The results are quite site specific dependent. However they show that regulation measures appear to be more effective than new technology investments. Higher energy prices could produce on their turn a deterioration of competitiveness and a threat for social goals.

This article illustrates a novel Curve Warning system for motorcycles which has been developed in the SAFERIDER project ( www.saferider-eu.org ) of the 7th EU FP, among other Advanced Rider Assistance Systems. The Curve Warning function (CW) described here follows a holistic approach, which combines road geometry, motorcycle dynamics, rider input and riding styles. The warning strategy is based on the correction of longitudinal dynamics derived from a previewed ideal manoeuvre (reference manoeuvre) continuously computed from the actual state of the vehicle. Under normal driving conditions the reference manoeuvre matches the rider’s and no correction is needed and no warning is given. But if large differences between actual and ideal accelerations are found the rider is warned to decelerate or brake. As soon as the correct value of deceleration is achieved the warning disappears, improving system acceptability. Warnings are given to the rider via an HMI, which uses a haptic accelerator throttle, a vibrating glove and helmet, and a visual display.