> In short, sensors on autonomous vehicles don’t work well in snow or rain—and that may never change.
There are sensors that can see through snow. They are very expensive, and only in the lab right now, but in the very near future there will (not "may") be processing packages that can fuse optical, radar, and other data into a coherent picture that will allow a computer to see a snow-covered road, through falling snow, better than a human could ever hope to.
I have seen a synthetic aperture radar system that can see through several inches of snow with such a resolution that it can detect paint lines beneath the snow and create a real-time picture of what the road looks like (potholes and all) that a human could never see.
It is too expensive today, but tomorrow?
Not only that, but with gyroscopes, rotation sensors, and real-time communications between vehicles, an automobile that can see through the snow like it is not there that can also talk to other cars will (not can) be able to know ahead of time what road and grip conditions are like based on vehicles that have previously and recently gone through the area. It will be able to adjust its driving to match conditions that are impossible for even the best human driver who has ever existed to detect.
Having 360-degree multi-band RADAR coverage, fused with optical, LiDAR, ultrasonic, and other technologies will result in systems that can: see that it is snowing, see how much snow there is, see the road through the snow, see ice beneath the snow, predict what the road conditions will be in a certain amount of time based on current and forecasted conditions, inform other cars about current conditions, know what conditions are at points on its route in the future and plan accordingly, and ultimately not care that it is snowing so long as it can cope with the conditions.
Today, hooking up some cameras and LIDAR to an Nvidia Jetson doesn't result in a car that can drive in the snow better than a human.
Tomorrow isn't today.
A human driving in heavy rain at night, hunched over the steering wheel squinting out into the distance, radio silenced to minimize distractions, hazard lights on to warn other drivers, never sure of the depth of any puddle that may be on the road, maybe a little tipsy from dinner and tired from a long day's work, will one day be seen as a wildly dangerous and unreasonable risk compared to automated systems with sensor suites that don't care if it is dark and raining and which can map the depth of any standing water with millimeter precision.