# Optimal Longitudinal Texture on Concrete Pavement to Reduce Lateral Vibration of Vehicles
## 6 Conclusions  
This study aimed to investigate the causes of lateral vibrations of vehicle driving over longitudinal texturing sections and develop an optimal longitudinal texturing specification to prevent lateral vibrations, an issue that has been reported intermittently on concrete pavement. To that end, the causes and evaluation methods for lateral vibration were established through an analysis of previous studies, laboratory and field tests, and finite element analysis. The major findings of this study are as follows:  
1. In the field test, the panel rating survey and acceleration investigation were performed in parallel. This showed that many lateral vibrations occurred in the 3 \(\times\) 3 \(\times\) Random section. Among the longitudinal texture applied in unhardened concrete sections, 3 \(\times\) 3 \(\times\) 16 mm and 3 \(\times\) 3 \(\times\) 19 mm showed the best results in the panel survey and acceleration data, respectively. When grooving patterns were applied to hardened concrete, the 2 \(\times\) 3 \(\times\) 19 mm showed higher performance than other specifications in all tests. It was found that the NGCS specifications require further improvement in the future. 2. As a result of the driving simulation test, it was analyzed that the occurrence of lateral vibration was less on the 2 \(\times\) 3 \(\times\) 16 mm and the 3 \(\times\) 3 \(\times\) 16 mm. It was found that it was clearly unfavorable to have lateral vibration in the 3 \(\times\) 3 \(\times\) Random section. There was no significant difference in the timing width, but it was evaluated that a section with a 2 mm timing width was a little advantageous for lateral vibration. 3. As a result of finite element analysis, it was found that 3 \(\times\) 3 \(\times\) 16 mm in the case of a 3 mm thinning width and 2 \(\times\) 3 \(\times\) 19 mm in the case of 2 mm are most advantageous for lateral vibration. Overall, it was evaluated that the narrower the timing width, the less the lateral vibration. It was found that the possibility of lateral vibration was high on the specifications with a wide center-to-center interval and on the random. As the result of reviewing the optimal longitudinal texturing specification based on the field test, finite element analysis, and driving simulation test, 3 \(\times\) 3 \(\times\) 16 mm and 2 \(\times\) 3 \(\times\) 19 mm were found to be the most effective in reducing lateral vibration. In the future, the authors intend to improve the longitudinal texture and grooving intervals \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Surface** & **Panel Survey** & **Acceleration Data** & **Structural** & **Laboratory** & **Applied Time** \\
**Specification** & **(Occurrence Rate, \%)** & **(Occurrence Rate, \%)** & **Analysis** & **Driving Test** & **(Before/After** \\
**(Max Range)** & **(Probability, \%)** & **(Probability, \%)** & **(Hardening)** \\ \hline
3 \(\times\) 3 \(\times\) 19 & 0.007 (1) & 0.032 (1) & 18.5 & 45.8 & Before hardening \\ \hline
3 \(\times\) 3 \(\times\) 16 & 0.004 (2) & 0.106 & 15.8 (3) & 25.8 (3) & Before hardening \\ \hline
4 \(\times\) 4 \(\times\) 14 & 0.136 & 0.084 & 17.3 & 40.1 (2) & After hardening \\ \hline
2 \(\times\) 3 \(\times\) 19 & 0.004 (2) & 0.040 (2) & 9.9 (1) & 44.9 & After hardening \\ \hline
2 \(\times\) 3 \(\times\) 16 & 0.017 & 0.045 (3) & 11.2 (2) & 17.4 (1) & After hardening \\ \hline
3 \(\times\) 3 \(\times\) Random & 0.173 & 0.155 & 20.0 & 83.6 & Before hardening \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Test results of longitudinal texturing specification. applied to pavement construction based on the findings of this study. In addition, the NGCS interval used for long-life and high-performance surfaces will be also improved through test application and evaluations with various specifications. Conceptualization, J.K.; Investigation, S.B. ; Supervision, D.S. ; Writing--original draft, S.R. ; Writing--review & editing, J.K. All authors have read and agreed to the published version of the manuscript.