Systems and method are provided for identifying free space between objects. The method includes retrieving, by a processor, a voxel grid around the vehicle wherein the voxel grid has a plurality of columns. The method further includes tracing, by the processor, lidar beams from a lidar system on the vehicle through the voxel grid, identifying, by the processor, a max subarray for each column in the voxel grid, classifying, by the processor, each column with a free space level, and outputting, by the processor, the classified columns as an image.