You’re cruising along at 65 miles per hour, faithfully adhering to Interstate 95’s speed limit. Suddenly the limit drops to 55 miles per hour, as it does in some locations, but you don’t notice. Thwack! You get a ticket, even though you thought you were obeying the law.
If only someone you were riding with had seen that 55 m.p.h. sign. If only your car had somehow “seen” it, and been technologically advanced enough to have slowed down on its own.