A computer-implemented system and method for detecting vehicle occupancy is provided. Light beam pulses emitted from a lidar system are applied to a passing vehicle. Scans of an object are generated from the light beam pulses. A signal is received from each of the beam pulses reflected at a point of reflection along a segment of the vehicle. A time is measured from when each beam pulse was emitted to receipt of the signal. A distance of the signal from the lidar system is calculated using the measured time. The points of reflection for that vehicle segment are positioned in relation to one another as a scan. The scans are compiled in a consecutive order according to the vehicle and a three-dimensional image of an interior of the vehicle is generated from the consecutive scans. A presence or absence of vehicle occupancy is determined based on the three-dimensional image.