The difference is simply non-realtime corner cases. Most of driving is relatively straightforward processing for the human brain. But every once in a while, som

The difference is simply non-realtime corner cases. Most of driving is relatively straightforward processing for the human brain. But every once in a while, something weird happens: humans controlling traffic in an unexpected way, something weird happens to the road and a new emergent order arises from communication with the driver, a cop comes to the window and tells you some detail about the way the road is closed. I don't drive much, but I still hit cases like this periodically, especially when driving through the canyons. From the user's perspective it's effectively the equivalent of taking transit, with very occasional non-realtime takeovers. By contrast, L4 can do all the things that don't require a human in the car at all, like cargo or getting to their next pickup.