> To the extent that we can agree on speed limits that delineate the difference between safe and unsafe behavior That can’t be the case though? If the posted l

> To the extent that we can agree on speed limits that delineate the difference between safe and unsafe behavior That can’t be the case though? If the posted limit is the boundary between safe and unsafe, drivers will be close to the limit all the time, and really in danger should they exceed it. The limits have to be set well away from that boundary, and the boundary itself has to assume the lowest common denominator of driver and vehicle. I think that's why average speed cameras feel especially unsporting. A reasonable driver in a modern car could beat a posted limit by 10% while remaining so far inside their safety envelope they wouldn't even notice.