Causing car crashes isn't hard (https://xkcd.com/1958/). That doesn't mean Car Crash™ International®'s decision-makers know how to do it: they probably don't even know what considerations go into traffic engineering, or how anyone can just buy road paint from that shop over there.
It's everybody's responsibility to keep Car Crash™ International® from existing; but failing that, it's everybody's responsibility to not tell them how to cause car crashes.