This would be trivial to solve with a vertical mounted LIDAR. You vertically mount it and if the horzontal distance measured level with the bumper of the car ar

This would be trivial to solve with a vertical mounted LIDAR. You vertically mount it and if the horzontal distance measured level with the bumper of the car are significantly closer than the horizontal distance at a lower angle you can classify that as a stationary object, if it's a continuous lengthening or shortening then it's a ramp. The classification is almost trivial (though the hardware may be expensive or difficult to implement for high speeds).