Road surface reconstruction plays a crucial role in autonomous driving, which can be used for road lane perception and autolabeling tasks. Recently, mesh-based road surface reconstruction algorithms show promising reconstruction results. However, these mesh-based methods suffer from slow speed and poor rendering quality. In contrast, the 3D Gaussian Splatting (3DGS) shows superior rendering speed and quality. Although 3DGS employs explicit Gaussian spheres to represent the scene, it lacks the ability to directly represent the geometric information of the scene. To address this limitation, we propose a novel large-scale road surface reconstruction approach based on 2D Gaussian Splatting (2DGS), named RoGS. The geometric shape of the road is explicitly represented using 2D Gaussian surfels, where each surfel stores color, semantics, and geometric information. Compared to Gaussian spheres, the Gaussian surfels aligns more closely with the physical reality of the road. Distinct from previous initialization methods that rely on point clouds for Gaussian spheres, we introduce a trajectory-based initialization for Gaussian surfels. Thanks to the explicit representation of the Gaussian surfels and a good initialization, our method achieves a significant acceleration while improving reconstruction quality. We achieve excellent results in reconstruction of roads surfaces in a variety of challenging real-world scenes.