Not only are car crashes less salient than train crashes, but also the converse effect: the inconvenience of car speed limits is more salient than the inconvenience of train speed limits, because you're the one driving.

I think the cycle feeds into itself though: part of the reason planes and trains are so safe is because of the extensive root-cause analysis of crashes, which routinely result in suggestions for improvement that make the rest of travel safer. Remove the investigations and you'd end up with more plane and train crashes.

When a car crashes, we just scrape up the debris and move on, after usually assigning blame to one of the drivers who ends up with higher insurance premiums or a lawsuit, assuming they survived. There's little effort to learn from the crashes.

Different risk profile. Trains generally don't have belts, crumple zones, padded surfaces, etc. Their risk profile dictates they avoid accidents. Cars are more chaotic, even in automated form. They are designed to crash safely as possible first, then anti-crash measures are added. Because trains depend soley on the anti crash measures, they must be stricter. The issue of harming dozens rather than a few humans also factors. Its an uneviable position for those responsible imho. Every move is going to be a little wrong and costly on some level.