# Impact of Putting on Traffic Safety: A Synthesis of Research Findings
## 3 Results and Discussion
### Weather Conditions  
Table 3 summarizes the impact of weather conditions on the relationship between rutting and accident rates across multiple studies. In dry conditions, ruts form depressions that serve as wheel paths, posing hazards when drivers attempt to steer out of them, especially if the rut depth is significant. However, additional risks arise when the pavement is wet due to reduced friction and potential water accumulation in ruts, increasing the risk of hydroplaning. Hydroplaning occurs when a layer of water causes the vehicle's tires to lose contact with the road surface, creating a separation due to fluid pressure under the tires [10]. Generally, weather conditions, particularly wet conditions, significantly exacerbate the negative impact of rutting on traffic safety. Field observations and simulation studies both underscore the heightened risks associated with wet ruts, highlighting the need for stricter rutting limits in areas with higher precipitation. As presented in Table 3, multiple field observation studies emphasize a more pronounced impact of rutting in wet conditions compared to dry conditions. [PERSON] et al. [27] explained that the reduction in hydroplaning speed due to rutting would reduce vehicle stability. [PERSON] et al. [31] argued that drivers' awareness of pavement with ruts is lower in bad weather conditions. Data describing the relationship between rutting and accident rates under different weather conditions were obtained from multiple studies [10; 14; 15; 52] to create Figure 5. In the original studies, the data were provided either as numerical values [52] or in graphical form [10; 14; 15]. Graphical data were extracted using the online \begin{table}
\begin{tabular}{c c c} \hline \hline
**Citation** & **Study Type** & **Findings Summary** \\ \hline [PERSON] et al. [15] & Field observation & Crash rates increase significantly with RD in rainy weather. \\ [PERSON] et al. [10] & Field observation & Crash rates decrease as RD increases, especially in dry conditions. \\ [PERSON] et al. [14] & Field observation & RD larger than 7.5 mm is more critical on wet pavement. \\ [PERSON] et al. [31] & Field observation & RD is more critical in rainy weather and night-time conditions. \\ \hline \multirow{3}{*}{[PERSON] [52]} & \multirow{3}{*}{Field observation} & - & Crash rates are higher under wet conditions. \\  & & - & Under wet conditions, higher RD might reduce the accident risk due to driver behavior changes. \\ \cline{1-1} [PERSON] [26] & Simulation & Increased water depth reduces tire–pavement adhesion, affecting safety. \\ [PERSON] et al. [33] & Simulation & Placement wetness increases sideslip risk and impacts LA. \\ \cline{1-1} [PERSON] et al. [35] & Simulation & Under wet conditions, RD has a very significant effect on the safety and stability of vehicles due to increased LA, RA, and LO, even with minor rut defects. \\ \cline{1-1}  & & - & Under wet conditions, the imbalance of the left rut and right rut can reduce vehicle stability. \\ \cline{1-1} [PERSON] et al. [36] & Simulation & - & Putting has a significant impact on the lateral and control stability of a vehicle. \\ \cline{1-1} [PERSON] et al. [29] & Simulation & Ponded ruts increase the risk of rollover and sideslip. \\ \cline{1-1} [PERSON] et al. [28] & Simulation & Water depth imbalance between right and left ruts increases sideslip risk; \\ \cline{1-1}  & & - & stability decreases at speeds \textgreater{} 120 km/h; speed should be reduced to \\ \cline{1-1} [PERSON] et al. [27] & Simulation & Increased RD (0–15 mm) decreases hydroplaning speed (90–80 km/h) as surface water flow depths increase (0 mm to 10 mm). \\ [PERSON] et al. [38] & Simulation & Water depth has minimal impact below 60 km/h but reduces stability above \\ \cline{1-1} [PERSON] and [PERSON] [25] & Simulation & Rutting has a limited impact on dry/wet pavement but reduces stability on snowy or icy surfaces. \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Impact of rutting on traffic safety under the effect of different weather conditions.