Transition to energy carriers with lower carbon dioxide emissions, such as renewable energy or sustainable biofuels, e.g., bioethanol, biodiesel, biomethane, hydrogenated vegetable oil (HVO) and fatty acid methyl esters (FAME)
[55].
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As a result, decision makers face challenges requiring them to pressure this sector to reduce its externalities, while simultaneously maintaining the economic model it helps to support
[56]. In this context, it is clear that top-level strategic actions aiming to regulate road transport typically promote implementation of innovative technological solutions, which may contribute to attaining both these aims. Digital solutions based on connectivity and automation of vehicles, as well as the paradigm of the sharing economy together with the transition to low-emission vehicle technologies (particularly electric vehicle and hydrogen vehicle technologies) are central elements of the European vision of smart and more eco-friendly transport
[57]. Innovativeness in transport is related with the search for methods to more efficiently utilise financial, management and organisational resources. This is a particularly important problem in view of the growing transport needs and limited resources. According to forecasts in Poland and the European Union, in the near future, innovativeness in transport should focus on the following problems
[58]:
- Transport methods and technologies;
- Planning, organisation and management of transport systems;
- Financing of transport in relation both to the maintenance and modernisation of existing resources, as well as new infrastructure, vehicle fleets and other resources.
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Transport methods and technologies;
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Planning, organisation and management of transport systems;
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Financing of transport in relation both to the maintenance and modernisation of existing resources, as well as new infrastructure, vehicle fleets and other resources.
One of the innovation priorities in road transport may include development of battery electric vehicles (BEV)
[59], which are becoming increasingly important, particularly in the privately owned automobile market. A battery electric vehicle (BEV) is an electric vehicle (EV), which is powered solely by the energy stored in batteries, with no other source (e.g., hydrogen, an internal combustion engine, etc.). Vehicles of the BEV type use an engine and an electric system instead of the internal combustion engine (ICE). These vehicles collect all the power from batteries and use it to power their engines, which additionally aids in powering their wheels
[60]. A significant component of costs in these vehicles is generated by batteries. Innovative designs for batteries on the one hand aim at reducing the adverse environmental impact, especially at the stage of their production and decommissioning, while on the other hand, innovative solutions focus on increasing the energy density and power of batteries, particularly in vehicles of medium and large load-carrying capacity. In the near future, this may be reached thanks to upgrades in existing lithium-ion technologies. Over a longer time, prospective new chemical technologies may replace lithium-ion batteries, ensuring further reduction of costs and improvement of their efficiency
[61].
An important role in the decarbonisation of the lorry segment may be played by flexible-fuel vehicles (FFV). In view of doubts related to the possible zero-emission technologies for lorries of large load-carrying capacity, it is crucial to develop options for combustion engines. Key innovations in this respect are related to improved fuel savings and reduction in harmful emissions. A limited hybrid type (e.g., the 48 V system, regenerative braking, also called recuperation) is particularly effective at reducing both high emissions and fuel consumption in vehicles equipped with combustion engines, which frequently stop and start to move again
[61]. At present, various types of dual-fuel vehicles are produced. Among them, one may distinguish, e.g., vehicles using petrol and LPG, hydrogen and petrol or petrol and diesel oil. Dual-fuel vehicles are low-cost burdens for the development of the hydrogen infrastructure prior to the introduction of fuel-cell-powered vehicles. They are considered to be a transition stage for vehicles powered with these cells, since they use the same fuel storage systems, safety systems, valves, safety system controls, etc. Moreover, this technology may be replicated on various engine platforms while incurring relative low costs
[62].
Novel engine architecture designs may bring about a greater increase in performance and efficiency parameters, although they are presently in their preliminary stages. Moreover, further integration of components is required in exhaust after-treatment systems to improve both their energy efficiency and effective removal of pollutant emissions.
In the near future, a particularly important role may be played by electric vehicles equipped with fuel cells. Vehicles with fuel cells powered by pure hydrogen are zero-emission vehicles, as in reality, the only local emission is water vapour. However, in this case, it is important to consider the complete fuel cycle, i.e., emissions related to the production, transport and supply of fuel. The basic primary source for the production of hydrogen is crucial for vehicles to be considered environmentally friendly. Hydrogen produced from renewable energy (e.g., wind or solar energy combined with electrolysis) and used in fuel cells may considerably reduce emissions. The latest studies concerning alternative fuels indicate that vehicles powered with fuel cells using hydrogen are the most promising technology in terms of reducing pollutant emissions in the fuel cycle
[63]. Fuel cells are considered increasingly promising, particularly as a solution limiting pollutant emissions by lorries. They offer a similar range of distance covered as conventional diesel engine vehicles; however, the high costs of its implementation are the main drawback of such a solution. For this reason, it is also necessary to implement innovations aiming at decreasing costs of fuel cells and the hydrogen tank, since these elements are, to a considerable degree, responsible for the total cost of fuel-cell-powered vehicles. These costs may be decreased by developing large-scale production, applying greater automation. In turn, fuel cells may play an increasingly important role in the decarbonisation of vehicles of medium and large load-carrying capacity, considering the relatively high ratio of generated energy to the mass of hydrogen in comparison to batteries. This aspect was also discussed by
[64][65][64,65]. It was stated that Poland has huge potential for the use of hydrogen as an alternative to conventional fuels used in the transport sector
[66]. This innovative application in transport has been described by many authors
[67].
A considerable challenge which may possibly change the entire infrastructure of land transport and travel is related to innovations leading to introduction of connected and autonomous vehicles. New vehicle technologies in this respect promise solutions in which sensors and specialist software will replace people as drivers
[68]. A priority in the development of CAV vehicles is to create safety foundations based on this technology. Innovative technologies, validation and testing procedures are crucial for the establishment of safety standards and lowering of implementation costs for this technology
[63]. Connected Autonomous Vehicles, i.e., those which are both combined and autonomous, are a technologically powerful area of potential great importance in the future, which has been shown in the publications of many authors
[69][70][71][72][69,70,71,72].