**3.1 Step 1: knowledge of the context of the variables to be evaluated and their development**

The main objective of this stage consists of bounded problems for which the fundamental parameters can be defined. For this activity, some elements are incorporated in the analysis and are obtained from a review of global, national, and local literature in relation to safety education programs and driving tests. As a result of this analysis, a list of specific questions involving six common variables around which two or three user-related questions are written is based on the comparative analysis of the necessary knowledge. Each question was obtained through a review of the literature, the resulting number of questions for each of the users of the infrastructure is as follows: 24 for drivers of vehicles, 24 for freight conductors, 24 for motorcycle users, 21 for bicycle users, and 21 for pedestrians.

## **3.2 Step 2: structuring the questionnaire and evaluation**

Within this stage, once the questions were established in the context of the selected variables two parallel processes will be carried out: the planning for the execution of the survey and the establishment of the weighting factors for the survey questions. The AHP method will be selected for this process, as it represents a structured and computerized process in which comparisons are made on a peer basis, which provides some evidence regarding the assessments made by experts of the Mexican Institute Transport (IMT) and the Autonomous University of Querétaro (UAQ ). To obtain the reason scales of the AHP methodology, we compared the set of peer evaluations for each question. The peer comparison was as follows: 1 = equal, 3 = moderate, 5 = strong, 7 = very strong, and 9 = extreme.

### **3.3 Step 3: experimental design and sample size for survey operation**

In this step, we will determine the size of the sample of users of the road examined which is calculated according to the number of inhabitants of the area [26] and the means of transport chosen by the users, as reported by Obregón and Betanzo [27].

$$n = \frac{N \ast Z\alpha^2 \, p \ast q}{d^2 \ast (N-1) + Z\alpha^2 \, \ast \, p \ast q} \tag{1}$$

Where *N* is the total number of inhabitants in the area (804 663 de Santiago de Queretaro), *Zα* = 1.96 (for a reliability 95%), *p* = expected proportion (in this case 5% = 0.05), *q* = 1 - p (in this case 1- 0,05 = 0,95), and *d* = precision (can be 1% to 3%; 2% was selected).

According to Eq. (1), 207 individuals were needed. This sample size considers individuals using the different means of transportation listed in **Table 1**, where it can be observed that freight vehicle, motorcycle, and bicycle users were the least frequent road users, with 1%, 1%, and 0.7%, respectively. To increase the reliability of these users, the sample size was increased to 20, for each of these modes. The number of validated questionnaires was 254.

The specific public areas for applying the survey were selected as a function of the type of transport infrastructure user: (1) public spaces, in which people spend at least 10 minutes completing some paperwork; (2) spaces around public schools, in which students move; and (3) recreational areas, in which users have more time to respond the survey (e.g. malls and public parks).

*Probability to Be Involved in a Road Accident: Transport User Socioeconomic Approach DOI: http://dx.doi.org/10.5772/intechopen.106325*


**Table 1.**

*Sample and user distribution by transport means in Santiago de Querétaro. Own elaboration by the distribution data from Ref. [27].*
