A method includes receiving sensor data from a plurality of sensors of a plurality of vehicles. The sensor data includes vehicle GPS data and sensed lane line data of the roadway. The method further includes creating a plurality of multi-layer bitmaps for each of the plurality of vehicles using the sensor data, fusing the plurality of the multi-layer bitmaps of each of the plurality of vehicles to create a fused multi-layer bitmap, creating a plurality of multi-layer probability density bitmaps using the fused multi-layer bitmap, extracting lane line data from the plurality of multi-layer probability density bitmaps, and creating the high-definition (HD) map of the roadway using the multi-layer probability density bitmaps and the lane line data extracted from the plurality of multi-layer probability density bitmaps.