Lidar becomes much less effective within rain/snow conditions, because it causes the infrared time-of-flight sensors to not be able to see past the weather conditions. An example video by Waymo[0] shows a silhouette of oncoming cars, but I don't believe lidar alone would be able to provide a quick enough detection mechanism. Comma.ai by George Hotz[1] was started to create a relatively inexpensive OTS solution that's vendor independent and crowdsource video to aid in development and training of self-driving algorithms.
[0] https://www.youtube.com/watch?v=TNUHjb5fbqs
[1] https://www.youtube.com/watch?v=t3XHXL9rzQM