# Analysis of Road Sign-Related Factors Affecting Driving Safety with Respect to City Size
## 4 Results
### Road Sign Recognition Survey  
The means for vehicle drivers to identify road information can be largely divided into road signs, navigation systems, and experience based on self-learning. The usage ratios of road information identification means were surveyed for each road type, including all road areas, intersections, and unknown areas. Navigation systems exhibited the highest usage ratio, accounting for an overwhelming proportion of 64.1% for unknown areas. On the other hand, road signs exhibited higher usage rates for all items compared to experience, with over 30% usage each corresponding to exits, intersections, and complex areas (Table 2).  
The primary uses and types of road signs, as well as road types, were surveyed to investigate the usage of road signs in greater detail. Acquisition of information regarding road facilities, such as rest areas and toll gates, was the most popular use of road signs, accounting for 58.6% of the total usage, followed by checking for exits (54.9%) and identification of difficult roads, such as multilevel intersections (53.2%). Signs depicting place names or directions were the most commonly used types of road signs, accounting for 79.9% of total usage, followed by road facility guide signs, e.g., those corresponding to rest areas and parking lots (63.3%), and distance signs depicting the remaining distance to a place (58.8%). The proportion accounted for by route signs (21.5%) within the total usage was relatively low as drivers in South Korea are usually familiar with the name-based guide system. Finally, expressway signs accounted for the highest share at 42.0% with respect to road signs sorted by road type, followed by general national highway signs (32.5%) and urban road name signs (25.5%). This was regarded as a reflection of South Korea's road environment, in which the road name system was established recently (2014) (Table 3).  
The road sign recognition survey estimated utilization, importance, contributions to route search, and driving safety of road signs based on a five-point scale. The importance of road signs exhibited the highest score with an average of 4.08, and contribution to route search (3.95) and contribution to driving safety (3.85) also corresponded to relatively high scores. However, the score of road sign utilization was relatively low, with an average of 3.61. The Pearson correlation coefficient between road sign utilization and driving safety was calculated to be 0.421 in the survey (significant at the 1% level), indicating a high correlation. Hence, road sign utilization can be considered to be directly proportional to its contribution to driving safety, indicating the need to explore measures to promote the use of road signs (Table 4).  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Road Area**} & \multicolumn{3}{c}{**Road Information Identification Means**} \\ \cline{2-4}  & **Road Sign** & **Navigation System (\%)** & **Experience** **(Self-Learning) (\%)** \\ \hline All driving areas & 26.5 & 47.9 & 25.5 \\ \hline Intersection areas & 32.2 & 43.7 & 24.1 \\ \hline Unknown areas & 27.8 & 64.1 & 8.1 \\ \hline Exits & 34.5 & 47.8 & 17.8 \\ \hline Complex areas (multi-intersections, etc.) & 30.3 & 52.0 & 17.8 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Road information identification means.