• Energy Research

In most urban areas, mobility is predominantly reliant on automobiles, leading to significant negative environmental impacts, such as noise pollution, air pollution, and greenhouse gas emissions. To meet the objectives of the Paris Agreement, urgent action is required to decarbonize the mobility sector. This necessitates the development of assessment and planning tools to create effective decarbonization scenarios. Urban mobility must evolve to reduce dependency on fossil fuels by increasing public transport options and promoting active modes of transportation. This research presents a methodology to estimate the modal share required to shift car users to active modes and public transport, thereby achieving future CO2 emission reduction targets in the road transport sector. A case study in Braga, Portugal, demonstrates that to meet the 2040 target of 59,150 tons of CO2, 63% of trips must be made using active modes (e.g., walking and cycling) and 32% by public transport.

Introduction: Active modes of transport can be defined as means of travel and transport at reduced speed, which take up little space on public roads and do not emit air pollutants or noise, being seen as an economic, social, and environmental asset, and a real alternative to motorized vehicles. Given its characteristics, the environmental benefits retrieved from active modes of transport should not serve only as a justification for its promotion but as a decisive and active factor in the scope of its actual use, which translates into the provision of pleasant and less polluted routes. Thus, the main objective of this paper is the development of a model for planning and generating urban routes for active modes that have a less negative influence on active users (pedestrians and cyclists) regarding their exposure to air and noise pollution. Methods: Conventional route planners are mostly designed to find the shortest, fastest, or less expensive route. In this research, the model to assign the best route will be presented for pedestrians and cyclists from an environmental point of view, by defining the least polluted, less noisy, and most health-friendly path. Based on the production of noise and air pollution maps, the model proposes the contamination of the network routes, which are used to determine healthoriented routes. The model is carried out through the calculation of the noise and pollution exposure for the routes found, compared to the shortest route. Conclusion: It was possible to conclude that less polluted routes may imply a small increase in the length of routes, but a significant gain in terms of reduction in exposure to PM10 and noise for active modes. Thus, the use of health-friendly routes can be seen as a matter of public health and a way for promoting more sustainable mobility. Available online 12 June 2022 (undefined)

The emission of GHG has been steadily increasing in the last few decades, largely facilitated by the transport sector, which has been responsible for more than two-thirds of the manmade emissions in Europe. In cities, one of the possible solutions to decrease the emissions from fossil fuel engines is to replace vehicles with electric ones. This solution can be applied to the urban public fleet, namely by replacing urban buses with electric vehicles. Thus, this research work focuses on the Portuguese case study, which serves as an example of achieving zero CO2 emissions from buses by 2034. This timeframe of replacing the current bus fleet, mostly powered by fossil fuels, with a fully electric fleet is proven to bring financial, environmental, and health benefits to the population. The pathway to the decarbonization of urban public transport will unequivocally contribute directly to the accomplishment of several UN Sustainable Development Goals (SDGs), such as the promotion of affordable and clean energy and sustainable cities and communities, as well as to the increasing climate action (SDGs 7, 11, and 13, respectively). In addition, it will provide an opportunity for the replacement of existing buses that are generally less efficient than electric buses, from both an energy and an environmental point of view. As a result of the methodology, the Portuguese urban bus fleet would be totally replaced by electric buses by 2034 (83% battery-electric and 17% hydrogen-electric), which results in zero CO2 emission from this type of public transport.

Street lighting design aims to ensure adequate night visibility conditions for both vehicular and pedestrian traffic as well as to improve security conditions for persons, goods and property in the neighbourhood. In addition to this, and in order to meet concerns about environmental protection and sustainable development, the design of street lighting should take into account the optimization of its energy efficiency, as excessive energy usage is associated with an increase in polluting emissions, namely CO2. Considering that street lighting generally presents a significant consumption of electricity that is often possible to reduce, the use of good design practices which will maximize the efficiency of lighting equipments and accessories as well as minimize the upward light emissions and adjust the intensity of lighting according to outdoor needs is crucial. The main goal of this work is to present a new simple tool which can assess street lighting performance in the context of energy efficiency. Three indicators were developed: one to evaluate lighting performance and two others to evaluate energy performance. These indicators were quantified and combined according to weighting and aggregation procedures, resulting in a synthetic score for the street lighting design. The assessment tool was applied to a business park located in Viana do Castelo, in Portugal, and the results are discussed.

The transport sector accounts for around one-quarter of the GHG emissions in Europe, and, in Portugal, it represents almost one-third of the total emissions to the atmosphere. Unfortunately, these emissions have increased in recent years. Hence, cities and countries need plans to decarbonize their public transport fleets, and, more specifically, to replace fossil-fueled buses with electric buses that produce zero CO2 emissions. Thus, the main objective of this paper is to present a method to decarbonize the bus fleet in Portugal by a scheduled replacement of the current fleet, which is fueled by fossil fuels, with a completely electric fleet, in fourteen years. The study shows that it is possible to replace all Portuguese urban bus fleets with electric vehicles considering that all vehicles will be replaced when reaching the age of 14 years. Replacing the urban bus fleet with zero-emission buses would aid policymakers and bus companies to reduce the GHGs, and therefore contribute to fulfilling the Sustainable Development Goals of the United Nations 2030 Agenda for Sustainable Development, namely, Goal 13—take urgent action to combat climate change and its impacts.

The application of sustainability principles on the definition of policies and actions for urban mobility relies on the promotion of less pollutant, economic, and more equitable modes of transport, such as walking and cycling, also known as smooth modes of transport. In this paper, a methodology is presented and described under the concept of healthy route generation. This integrates the contamination of the smooth modes of transport network, according to the noise levels and air pollution indices of the urban environment in which it is located, with the main objective of reducing the exposure level and the risk of development of respiratory and cardiovascular diseases. Healthy routes can be applied to attract and promote the use of smooth modes of transport in a regular basis in urban environments.

In 2020, only 0.9% of buses running in European Union countries were electric, with 93.5% still being diesel-powered. The Sustainable and Smart Mobility Strategy set out by the European Commission targets a reduction of at least 55% in greenhouse gas emissions by 2023 and the achievement of climate neutrality by 2050. These targets will only be met by a shift to sustainable mobility, which comprises the introduction of electric vehicles in cities and the adoption of battery electric vehicles (BEV) for urban public transport. Thus, a literature review on “electrification of bus fleets” was conducted, focusing on the practices adopted for the replacement of polluting buses with electric-powered ones. A total of 62 documents were included in the final investigation, and their results were used to conduct a SWOT analysis. It is possible to conclude that BEBs are an important asset for cities to decarbonize the transport sector and that they are more cost-effective than diesel buses. On the other hand, some attention needs to be given to the generation of energy that will feed the charging of batteries because the use of fossil fuel energy sources can jeopardize the environmental benefits of BEBs.