# A Simulation of Tire Hydroplaning Based on Laser Scanning of Road Surfaces
## 2 Background of Research
### Road Profile Characteristics and Anti-Slip Indexes  
The texture of road surfaces at different scales directly affects the contact characteristics between tire treads and the road surface, thereby impacting the road's anti-skid performance, noise levels, ride comfort, and tire wear. Based on the wavelength of the texture, the International Association for Road Surface Technology (The Permanent International Association of Road Congress, abbreviated as PIARC) [19] categorizes road surface textures into four types: unevenness, macro-texture, macroscopic texture, and microscopic texture. The classification indicators of pavement texture and their impact on different pavement performance are shown in Table 1.  
Micro-texture of the road surface refers to wavelengths and amplitudes both less than 0.5 mm, primarily manifesting as the undulating characteristics of the exposed aggregate surface. This is related to the mineral composition of the aggregates, lithology, and the source of the aggregates (natural or synthetic). It ensures basic friction under low-speed dry road conditions and rapidly breaks down the thin water film on wet roads, increasing the contact area between the tire and the road surface, thereby enhancing anti-skid performance [29]. Macro-texture refers to wavelengths ranging from 0.5 to 50 mm and amplitudes from 0.1 to 20 mm, mainly characterized by the undulating properties between aggregates on the road surface. This is associated with the geometric shape, gradation composition, and construction techniques of the aggregates. Under high-speed wet road conditions, it provides rapid drainage channels, reducing the likelihood of water skidding and ensuring driving safety [22]. Coarse texture refers to wavelengths ranging from 50 to 500 mm and amplitudes from 0.1 to 50 mm, primarily resulting from irregular surfaces caused by non-standard operations during construction. These can easily lead to localized  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Classify** & **Micro-Texture** & **Macro-Texture** & **Coarse Texture** & **Irregularity Degree** \\ \hline wavelength (mm) & \textless{}0.5 & 0.5–50 & 50–500 & 500 \\ amplitude (mm) & \textless{}0.5 & 0.1–20 & 0.1–50 & — — \\ The performance of the impact & adhesion & drainability & driving comfort & driving comfort \\ \hline \end{tabular}
\end{table}
Table 1: Wavelengths of pavement surface texture.  
Figure 4: Schematic diagram of laser beam movement route.  
water accumulation, increase tire rolling resistance, and generate significant road noise. During construction, efforts should be made to avoid the formation of coarse texture. Unveunness refers to wavelengths greater than 500 mm, mainly caused by serious quality issues during asphalt paving or significant damage and uneven settlement during use. This can result in large areas of water accumulation on the road surface, causing severe noise and affecting passenger comfort. The formation of unevenness should be avoided.  
The macro- and micro-texture of the road surface is an important factor affecting the anti-slip performance of the road surface. Different levels of macro- and micro-texture will directly affect the contact characteristics of the road surface between the tire and the water. However, at present, the simulation techniques of micro-texture are limited. This paper will mainly focus on the influence of different macro-texture levels on the anti-slip performance of the road surface.