Provided herein is a method, apparatus, and computer program product for identifying locations along a road segment as a tunnel based on point cloud data. Methods may include: receiving point cloud data representative of an environment of a trajectory along a road segment; generating, from the point cloud data, one or more two-dimensional images in one or more corresponding planes orthogonal to the trajectory; determining, for the one or more two-dimensional images, a probability as to whether a respective two-dimensional image is captured within a tunnel along the road segment; and classifying a point along the road segment at a position corresponding to a respective one of the one or more two-dimensional images as a tunnel point in response to the probability as to whether the respective two-dimensional image is captured within a tunnel along the road segment satisfying a predetermined value.