Generally that's because to fight it, they'd have to visit the town's courthouse or spend money on a lawyer. If I were the one choosing the fines, and I lacked

Generally that's because to fight it, they'd have to visit the town's courthouse or spend money on a lawyer. If I were the one choosing the fines, and I lacked a soul, I'd choose a fine amount that maximized #speeders * $cost * %fighting.