Public Health-Led Insights on Electric Micro-mobility Adoption and Use: a Scoping Review

This review derives from a larger, primary scoping exercise that identified the determinants of EMM use from a public health perspective, but also with the objective to gather all available research regarding health and safety impacts derived from the use of EMM including physical activity, noise and air pollution, safety risk, social cohesion, accessibility, and more. For this primary review, queries were carried out according to a systematic search strategy, using a combination of keywords covering EMM (i.e. the vehicles) AND health and safety pathways and mechanisms AND health, safety, and well-being outcomes (see an example in Table 1). The pathway and mechanism categories analysed were the following: air pollution, noise, thermal comfort, route choice and natural outdoor environments, physical activity, safety and crash risk, trip purpose and motivation, accessibility and connectivity, infrastructure and management, regulation and compliance, use and behavior, Covid-19 and future trends. We used the AND Boolean operator to create the final queries (shown in Table 1). The search was conducted in four different databases: PubMed, Web of Science (WoS), Scopus, and Transport Research International Documentation (TRID), to cover and reach all the topical dimensions: Web of Science and Scopus provide a multidisciplinary body of literature, PubMed covers biomedical and health sciences, and TRID that covers transportation sciences. Prior to the present research stage, to our knowledge, researchers reached a consensus on predefined umbrella health and safety pathway categories, that were thought to be relevant in the discussion on health and safety impacts of EMM [40].

All searches were limited to the English language, and to articles published between 2010 and 2021. All types of study designs were included: scoping review, systematic review, meta-analysis, ecological, longitudinal, cross-sectional, case–control, intervention, and observational. For review inclusion, the studies had to cover determinants of EMM use and a health or safety pathway or mechanism of EMM linking to human health. Searches in all four databases resulted in a total of 12,214 hits, as shown in Table 2 and Fig. 1.

Only studies covering EMM vehicles that met the definition provided above were included (i.e. light vehicles, powered by electricity, not exceeding a speed of 25 km/h). Therefore, e-mopeds, e-motorcycles, and speed-pedelecs were not included, as they likely exceed the speed definition. The scoping review is based on the international literature if authors of papers reviewed have judged discussed concepts to be universally relevant in the discussion on EMM determinants, irrespective of geographical context. However, the presented case studies were selected only for European settings, as the aim of this study is to reflect the current European EMM landscape, and it was thought that EMM determinants might vary in other parts of the world in accordance with local regulations, transport systems, user needs, behaviours, and experiences.

Regarding the current scoping review on the determinants of EMM, of all the articles identified as eligible, we only focused on the publications dealing with determinants. A total of 67 articles were included for analysis, covering the enablers, motivations, barriers, and deterrents. We decided to classify the determinants between contextual enablers and barriers that refer to factors that operate at a larger or more macro level and that are related to the existing legal frameworks, transport system provisions, availability of dedicated infrastructure, technological enablers, and other wider, contextual factors (e.g. topography, climate, etc.); and personal motivations and deterrents, that are those relating to individuals’ preferences and intrinsic behaviours and depend on personal factors such as age, income, occupation, and lifestyle, including convenience, cost, time, health, environmental concerns, and social status.

All identified records were uploaded to the Mendeley references management software (https://​www.​mendeley.​com). Duplicate publications were removed, and title and abstract screening were conducted. Publications meeting the established inclusion criteria were selected for full-text screening. Full texts were sourced, and full text screening was conducted. A descriptive analysis was carried out to gather information about the selected studies including their publication year, location, methodology, and outcomes. The main outcomes related to the specific topic of the review were identified and listed. This process was done by two reviewers, AB and NM, and a narrative summary was given for each outcome. The significance of the findings in relation to the research question and implications for research, policy, and practice were discussed, highlighting any evidence gaps and important priorities. All steps were carried out independently by the two researchers (AB, NM). Any discrepancies were resolved by consensus.

As the result of our search strategy for our primary review, and after the removal of duplicates, 4277 articles were title-screened, 2552 articles were abstract-screened, and 721 articles were full-text-screened (Fig. 1). After the full-text screening, 200 articles qualified for review inclusion. Additional cross-reading and reference screening added another 17 articles. Finally, 217 articles were included in the larger, primary scoping review, covering the landscape of EMM determinants and health and safety pathways. For the analysis presented here, of these 217 articles, 67 were identified to be specifically related to the determinants of EMM usage (i.e. in the European Region).

Of the 67 articles included in this scoping review, 85% (n = 57) were peer-reviewed research articles, and 15% (n = 10) were grey literature. Most of the peer-reviewed research was published in transport and mobility-related journals (47%), as well as in health and environmental science journals (32%). The grey literature contained eight reports and one project presentation. Regarding the time of publication, there was a steep increase in research on EMM since 2018, and 76% (n = 51) of the articles were published between 2018 and 2021. Of the total number of 67 publications, 76% (n = 51) presented an observational/cross-sectional research design, while 24% (n = 16) were literature reviews.

This section lays out the determinants of EMM identified across the included studies. Table 3 and Table 4 summarise the contextual enablers and barriers, as well as individuals’ motivations for and deterrents against engaging in EMM use and list determinants according to commonness of reporting (i.e. most to least commonly reported).

Regarding contextual enablers, EMM was found to offer a relatively cheap, flexible, ad hoc, and fast way to move within urban areas, expanding the area riders can easily travel without a car or a driving licence, thereby increasing accessibility and connectivity within cities. Although to date, findings on EMM being a first- and last-mile solution are mixed [16, 23, 32], users seem to appreciate the convenience of vehicles that are lightweight, foldable, and can be carried on public transport. Moreover, the provision of dedicated infrastructure for EMM appears to be a crucial element, with which to foster and maintain safe usage. Our findings highlight the lack of appropriate infrastructure and end-of-trip facilities as the main contextual barrier.

Considering personal motivations to adopt EMM, users value convenience, reduced travel times, low cost, low physical activity requirements, environmental sustainability, component innovation, and the thrill and enjoyment of riding. Regarding convenience, users seem to value freedom, and flexibility in deciding on travel routes and planning, reducing car dependence, congestion, and other car-related inconveniences. When factoring in waiting times for public transport, rush hour traffic, and time spent looking for car parking spaces, EMM was assessed to be an attractive time-saving competitor to other modes of transport. Economic savings seems to also be an important personal argument for why people might engage in EMM use, especially when compared to car use. However, high vehicle acquisition and maintenance costs were also reported as a contextual barrier when referring to privately owned EMM vehicles.

Physical activity was not found to be a significant factor in attracting new EMM users. Rather, it was the lower physical activity levels that are required to operate EMM which attracted users, especially in the case of e-bikes. EMM modes appear to be appealing for people with no or little interest in the physical activity component of transportation. Most importantly, EMM seems to be more suitable for everyday use in adverse conditions (cold weather, wearing formal clothing, physical tiredness) than other traditional active transport modes, which would indicate a growth potential for EMM, in some geographies and within a wider variety of social groups with different travel needs. Contrarily, some studies suggested that EMM use was weather dependent, and not particularly suited to the usual conditions of rain, wind, cold, heat, or darkness.

Regarding personal motivations, reviewed studies have found how the environmental perception that is linked to these vehicles favours their adoption, particularly among the more environmentally aware groups of younger people. This generalised perception of environmental friendliness might clash with more recent sustainability analyses which conclude that the rise of EMM in cities is causing an actual increase in emissions [37, 73]. Other appealing factors mentioned less frequently include the technological and innovation components of EMM and the enjoyability and personal experience of riding. Interestingly, the proper device technology was also identified as a barrier, including the increased weight of the vehicles and their batteries, and concerns about potential technical failures (e.g. battery explosion anxiety).

In relation to other contextual barriers, apart from the absence of satisfactory infrastructure, the limited capacity of EMM to cover all terrains and trip characteristics was also mentioned, together with the reduced carrying or loading capacities of goods and passengers. The most important personal deterrents to engaging in EMM use concerned safety and the increased accident and injury risk perception. The presence of disruptive factors such as dense motorised traffic, traffic speed, noise, and air pollution, together with the fear of theft and vandalism, were further identified as important deterrents.

Lastly, for the specific case of both docked and free-floating sharing systems, reviewed studies highlighted the reduced burdens of ownership and the convenience linked to the low levels of care and maintenance that are required as the main motivators to use these systems. Yet, docking locations, vehicle availability, and unequal vehicle distribution across the city were identified as the main contextual barriers. Likewise, personal deterrents were technological problems, lack of awareness of the features of the system, difficulty in determining how to use the system, as well as system cost and high fees. Moreover, these shared systems are sometimes perceived as excluding the socioeconomically disadvantaged or elderly people as the service requires a credit or debit card as a point of entry, as well as possession of a smartphone.

Our findings suggest that EMM has the potential to provide mobility opportunities, diversify transport, and possibly even provide environmental and health benefits if they are properly managed. The introduction of e-bikes, and e-scooters, may have positive outcomes if they are well integrated into the existing (public) transport structures. EMM needs to be integrated well into the existing (public) transport system, facilitate first- and last-mile mobility, and particularly encourage mode shifts from private motorised transport (i.e. cars, motorcycles), to reap the largest environmental and health benefits. To do so, it is necessary to increase the availability and accessibility of EMM options, such as through the expansion of charging infrastructure and the creation of dedicated lanes. Regarding parking and storage, safe, secure, and vehicle-appropriate parking spaces are needed at different locations (e.g. work, public transport stops, kindergartens, shopping centres, other points of interest), including overnight parking. Additionally, measures are required to improve the affordability of privately owned devices, such as subsidies or reduced tariffs. EMM use is thought to provide a range of benefits at the individual level, such as perceived increased well-being, enjoyability, flexibility and freedom, and money- and time-savings that can be capitalised on.

For EMM to become a viable and safe mobility alternative for increasing numbers of people around Europe, a clear legal framework that prevents conflicts with other road users is needed. This literature review has identified traffic safety concerns as the main barrier for adoption among potential users. Authorities should not only address this issue, but also create and disseminate clear rules and guidance regarding which infrastructures EMM is supposed to use (e.g. this would work best if they are designated and segregated), and which other safety and public order requirements are in place (e.g. parking requirements, maximum speeds allowed, minimum user age, safety, and visibility gear). Moreover, clear enforcement of established rules is also necessary to avoid conflicts and ensure a safe co-existence, and appropriate public space allocation and usage (e.g. avoidance of “cluttering”).

Several measures could be implemented to make the use of EMM more socially accessible. In the first instance, design could focus on easing access and use for certain collectives (e.g. women, elderly, cargo, and delivery), thus reducing the vehicle weight and increasing stability and manoeuvrability. Vehicles could be made generally more cargo- and family-friendly by allowing installations to carry goods and child seats. Sharing systems could offer alternative access paths, that do not necessarily involve access to the latest smartphone technology or using debit and credit cards. This would require an alternative payment system with a physical infrastructure such as kiosks or rental stations to pay by cash. Also, pre-paid cards could be accepted so they can be loaded with funds prior to the rental. These measures would help reduce discrimination against certain communities. Our review has also found that there is a strong identification of EMM as a sustainable alternative to traditional transport modes. This contrasts heavily with recent literature pointing to the contrary, suggesting that for instance when EMM replaces other active forms of transport such as walking or biking it would be causing a damage to the environment by increasing emissions, while there exist environmental challenges posed by the manufacture and disposal of batteries, if the whole life cycle of these vehicles is examined [35, 67, 74‐76]. These authors highlight the need to raise awareness about the real implications of EMM and its impact on the environment. Hence, it seems that EMM environmental benefits may be overestimated by some individuals, as this information is not widely known by its current or potential users.

It is important to note that all these policy recommendations will also depend on the different levels of government and stakeholders that may be involved in implementing policy changes related to EMM, as well as the potential barriers and facilitators to implementing policy changes. At the local level, decisions related to EMM may include the installation of charging infrastructure and the creation of dedicated lanes. Local governments may also be responsible for enforcing safety regulations and monitoring the use of EMM in their jurisdictions. At the state level, decisions may include regulations related to the operation and licencing of EMM companies and operators, as well as the development of policies to promote their use. At the country level, decisions may include regulations related to safety and operation, as well as the development of national transportation policies that incorporate EMM and corresponding regulatory frameworks. In any case, the level of government that is responsible for making decisions related to EMM may vary depending on the specific issue and the country or region. The same applies to the success of these potential measures. Successes could vary across different towns and cities, as different jurisdictions may have different needs and resources. Success in certain locations than others depends on factors such as population density, existing transportation infrastructure, and cultural attitudes towards EMM. Therefore, it is crucial to consider the local context and the specific needs of different communities when developing and implementing policy recommendations related to EMM. Finally, additional research, discussion, and communication are essential among authorities, researchers, and practitioners to improve current mobility systems, make evidence-based decisions, and potentiate positive (environmental and health) impacts of EMM use, while mitigating negative effects.