# Influence of the Surface Texture Parameters of Asphalt  
Pavement on Light Reflection Characteristics  
[PERSON]  
1 Hunan Key Laboratory of Smart Roadway and Cooperative Vehicle-Infrastructure Systems, Changsha University of Science & Technology, Changsha 410114, China: [EMAIL_ADDRESS]  
[PERSON]  
2 School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China: [EMAIL_ADDRESS]  
2 [EMAIL_ADDRESS]  
[PERSON]  
2 School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China: [EMAIL_ADDRESS]  
[PERSON]  
2 School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China: [EMAIL_ADDRESS]  
[PERSON]  
2 School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China: [EMAIL_ADDRESS]  
[PERSON]  
2 School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China: [EMAIL_ADDRESS]  
[PERSON]  
2 School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China: x10114  
rately obtain the optical reflectance characteristics of actual roads and improve the accuracy of road-lighting design. However, the complexity of laboratory measurements and the backwardness of related measuring instruments restrict the accuracy of acquiring the reduced luminance coefficient. Therefore, the CIE recommends using the retroreflectivity coefficient, \(R_{\text{L}}\), which is measured at the road site, to indicate the reflective characteristics of the pavement surface [5]. The pavement's surface texture is defined as any deviation of the pavement surface from the actual plane [15]. The World Road Association (known as PIARC) [16] classifies the surface structure of asphalt pavement into four types: microtexture, macrotexture, macrostructure, and uneven, based on the wavelength in the horizontal direction, the amplitude in the vertical direction, the power spectral characteristics of asphalt pavement, and the possible impact on road users, where the microtexture is less than 0.5 mm and the macrotexture is in the range of 0.5-50.0 mm [17]. The texture depends on the composition of the top layer of the pavement material, while the reflectivity of the surface is determined by the micro- and macrotexture [18]. Macrotexture refers to irregularities in the rough texture of the road surface, which mainly depend on the nature of the aggregate (such as its size, grading, shape, and distribution), the nominal maximum size of the aggregate, and the nature of the asphalt mixture (such as the content, mix design, and void ratio) [19; 20; 21]. The macrotexture depends mainly on the roughness of the road surface, controls the noise between the tires and the road surface as well as friction at high speeds, and mainly provides drainage in rainy weather [22]. Microtexture refers to the fine structural irregularities on the surfaces of the aggregate particles, generally reaching the micrometer level, and is mainly related to the mineral composition of the particles [23]. The microtexture interacts with rubber tires at the molecular scale and provides adhesion. Thus, it is important on both wet and dry pavement [24; 25], and it also has important antislip properties [26]. Due to the low accuracy of traditional pavement texture measurement in the past, a set of ultra-high-speed line laser-testing systems, based on an image-recognition method, has been developed, which can significantly improve the efficiency and accuracy of 3D data measurement for the structure and texture morphology of asphalt pavement [27]. [PERSON] et al. [28; 29] measured the surface-texture characteristics of three typical grades of asphalt mixtures, AC, SMA, and OGFC, according to the experimental data to establish a regression model with the mass ratio, the product of particle size, and the average depth of the structure of the dependent variable.