## 3 Methodology
### Survey  
The revealed preference (RP) survey used in Braga to collect information from users and potential users of shared e-scooters was structured in three different parts. Firstly, the respondents had to answer if they use or do not use the shared e-scooter service in Braga. Then, if the answer was negative, the respondents were forwarded to a selection of questions regarding the main factors for them not to use the service, and if they were willing to start using shared e-scooters if the current perceived negative factors were solved. If the respondents use the service, then they were forwarded to a series of questions regarding the main motivations for them to use this mode of transport, and how they use the vehicle and the service across the municipality (e.g., origin-destination, frequency). In the end, all respondents were asked socioeconomic questions. In order to better identify the profile of the population (actual and potential users) that is served by shared e-scooters, some key aspects were collected, as shown in Table 2.  
Figure 3: Area served by shared e-scooters in Braga. The online and face-to-face survey was disseminated from 24 January to 10 July 2022 in downtown Braga and near school districts, as well as with the University of Minho community (i.e., students and staff); 541 answers were collected, but 108 had to be discarded due to inconsistent answers, which resulted in 433 valid answers to estimate the results. The sampling of respondents was around locations in the vicinity of shared e-scooters stations that comprise the main traffic generators in the city, such as educational poles (University of Minho and colleges) [4]. The above sample was statistically representative of the population of users at a 95% confidence level (margin of error of 2%). Following previous research, shared e-scooters are mostly used by younger people [63; 64], and heavy e-scooter traffic is expected to occur in downtown and university campus areas [65; 66]. It is important to mention that from the 433 valid answers, 78 represent current users of shared e-scooters in Braga, while 355 represent potential users (i.e., people that do not use shared e-scooters but could start using if some improvements were made) of the service. This sample size (N = 433) was calculated to represent a margin of error of 5%, with a confidence level of 95% [67], from a population of 193,324 people who live in Braga [62]. After the data collection, the correlation of the results was obtained through the chi-square goodness of fit tests, as shown in equation 1, which allows for testing whether the observed distribution of socioeconomic categories among users and potential users of shared e-scooters differs from or has similarities with the distribution of the population in Braga [68], that is, if socioeconomic characteristics (categories) of respondents (users and potential users) differ from or are related to the general profile of the resident population in Braga according to the 2021 census results [62]. \[X^{2}\ =\ \sum_{i\ =\ 1}^{k}\frac{(O_{i}-E_{i})^{2}}{E_{i}} \tag{1}\]  
where \(X^{2}\) is the chi-square test statistic, \(\sum\) is the summation operator, \(O\) is the observed frequency in category \(i\), and \(E\) is the absolute expected frequency in category \(i\). Firstly, data regarding the current users' profiles were evaluated to assess the present equity of the service in Braga. Then data from users and potential users were evaluated to estimate the potential equity of the shared e-scooters if improvements in the provision of the service are made.