I would like to create a map of the roads of a small region. The car has imu, gps, accurate odometry msg using robot_localization pkg. There is a front-facing lidar too but it has a smaller range. So, for now, I am looking for a map without lidar if possible though a 64-layer Velodyne lidar is coming soon. I found some mapping techniques such as gmapping, and hector-slam are for indoor mapping only. Rtab map requires a depth camera that I do not have. For autonomous navigation, I think a map is essential. I am not sure whether I need a 2D map or a 3D map. I would appreciate any suggestions.

So, how can I proceed with the current resources I have? Even if it requires a 360 lidar, which approach should I employ? At least I can create a map in the gazebo simulation with the lidar for now.