# Impact of Putting on Traffic Safety: A Synthesis of Research Findings
## 3 Results and Discussion
### Literature Analysis  
#### 3.2.1 Impact of Various Factors on Rutting and Traffic Safety Interactions  
The perceived significance of rutting on traffic safety may vary due to a variety of factors. Table 2 summarizes the impact of ten factors on the criticality of rutting on traffic safety, including data type, weather conditions, lighting conditions, driving speed, driving trajectories, and road geometry. The results showed that the mode of investigation in terms of the use of simulation and field observation data was the most impactful factor on the perceived criticality of rutting. Simulation-based studies were found to be more likely to suggest a significant impact of rutting on traffic safety.  
Several other factors were found to exacerbate the perceived impact of rutting on traffic safety. Rainy weather, resulting in wet pavement and water pooling, generally increases the impact of rutting by reducing skid resistance and heightening the potential for hydroplaning [27]. Additionally, rainy conditions can reduce the visibility of ruts [12]. Path changes while driving can increase the difficulty of steering control, leading to higher accident risks [10]. Curved roads increase the significance of rutting as they become less identifiable and more dangerous, especially in the presence of water [14]. Higher speeds exacerbate the impact of rutting on traffic safety [35; 37]. Rutting is more hazardous at nighttime due to lower visibility and reduced ability to identify and adjust driving behaviors  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Study** & **Rut Index** & **Safety Index** \\ \hline [PERSON] et al. [29] & Rut depth, side slope & Vehicle rollover (based on LTR) and Vehicle \\  & & sideslip (based SI) \\ [PERSON] et al. [32] & Rut depth, rutting average width, & Vehicle Steering stability based on maximum slide \\  & side angle of rut & angle and RA \\ [PERSON] et al. [33] & Width–height ratio of rut & Sideslip stability based on LA and slip angle and \\  & & rollover stability based on LTR and RA \\ [PERSON] et al. [30] & Rut depth & Rotation degree of the steering wheel \\ [PERSON] and [PERSON] [26] & Rut depth & Coefficient of adhesion of the tire to the surface \\ [PERSON] and & Rut depth & Custom vehicle-stability criterion \\ [PERSON] [25] & Rut depth & \\ [PERSON] et al. [27] & Rut depth & Hydroplaning speed of pavement \\ [PERSON] et al. [35] & Rut depth, width–height ratio & Lateral acceleration, roll angle, YA, lateral offset \\ [PERSON] et al. [37] & Rut depth & Braking distance \\ [PERSON] et al. [38] & Rut depth & LO, LA \\ [PERSON] et al. [39] & Rut depth & Angles of departure and dynamic load of the \\  & & wheel when the vehicle leaves or enters the rut \\ [PERSON] et al. [28] & Rut depth & Risk of lateral slip \\ [PERSON] et al. [36] & Rut width, rut length, rut depth & LO, LA \\ \hline \hline \end{tabular}
\end{table}
Table 1: Impact of rutting on traffic safety based on simulation studies.  
accordingly [31]. Light vehicles are more prone to putting, and vehicles with wheel widths larger than the rut width are more likely to be impacted [40]. Moreover, the study location can significantly impact the findings, making it challenging to generalize results from one specific country to others. However, the impact of annual average daily traffic (AADT) is complex and cannot be understood without considering speed.