## 2 Methodology
### Procedures  
The experiment was conducted according to the National Ethical Guidelines 2017, of the Philippine Research Ethics board. Prior to the experiment, the participants were required to fill out a consent form, including the personal characteristics such as age, gender, educational attainment, as well as their personal driving experiences. For those with driving experience, the participants were also asked about their driving characteristics, such as frequency of driving, number of licensed driving years, and whether they attended driving schools. For nondrivers, they could skip the questions on driving experience and proceed immediately to the matching test. The instructions, survey form, and the matching test materials were all written in English. After submitting the required information, the participants were directed to the matching test screen to assess the comprehensibility of the 73 traffic signs. As shown in Figure 2, the selection of traffic signs was based on the location of major roads, such as the C-5 road in Quezon City, where most of the violations and accidents occurred. Seventy-three traffic signs were selected and then categorized according to their traffic sign type and display condition (See Figure 3), to determine if these factors influence a driver's comprehension. The current study adopted the matching test format from [PERSON] and [PERSON] [33], where the participants matched the traffic sign with the most appropriate referent name based on \"Highways safety design standards Part 2: Road signs and pavement markings\" by the Department of Public Works and Highways [12]. For the matching test, the 73 traffic signs were divided into three groups. The order of the traffic signs was randomized, but signs that were expected to have a similar referent name were included in one group to minimize guessing from participants. When the traffic sign was flashed on the screen, the participant had to click the letter that corresponded to the referent name of the traffic sign on the screen. If the referent name matched the traffic sign, the time it took the participant to click the letter was recorded as the matching time. Otherwise, matching time was not recorded for the incorrect referent name. \begin{table}
\begin{tabular}{l l c c c c c c} \hline \hline
**Demographic** & \multirow{2}{*}{**Categories**} & \multicolumn{2}{c}{**Drivers**} & \multicolumn{2}{c}{**Non-Drivers**} & \multicolumn{2}{c}{**All**} \\
**Characteristics** & & **No.** & **\%** & **No.** & **\%** & **No.** & **\%** \\ \hline \multirow{3}{*}{Age} & 18–27 & 11 & 18\% & 13 & 22\% & 24 & 40\% \\  & 28–37 & 8 & 13\% & 10 & 17\% & 18 & 30\% \\  & 38–57 & 11 & 18\% & 7 & 12\% & 18 & 30\% \\ \hline \multirow{3}{*}{Gender} & Male & 21 & 35\% & 17 & 28\% & 38 & 63\% \\  & Female & 9 & 15\% & 13 & 22\% & 22 & 37\% \\ \hline \multirow{3}{*}{Educational} & High School Level & 6 & 10\% & 6 & 10\% & 12 & 20\% \\  & College Undergraduate & 14 & 23\% & 15 & 25\% & 29 & 48\% \\ \cline{1-1}  & College Graduate & 10 & 17\% & 9 & 15\% & 19 & 32\% \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Demographic Characteristics of Participants. The second part of the experiment was about the subjective rating of the cognitive design features for the 73 traffic signs, which were also assessed to measure the effectiveness of the sign's design. Participants were given an evaluation sheet to give subjective ratings between 1 and 5 points for familiarity (1 = very unfamiliar, 5 = very familiar), concreteness (1 = definitely abstract, 5 = definitely concrete), complexity (1 = very complex, 5 = very simple), and semantic distance (1 = very weakly related, 5 = very strongly related) for each traffic sign presented in color and printed in English on the sheet. For example, when the \"No Parking\" sign was shown, the participant was asked to assess the traffic sign based on concreteness. This was repeated with all remaining traffic signs until all signs had been assessed using the four cognitive design features.