Low probability selective and/or random enforcement is a pernicious effect. The real effect of a speed limit that’s too low according to most road users is not

Low probability selective and/or random enforcement is a pernicious effect. The real effect of a speed limit that’s too low according to most road users is not to declare society’s intentions about how you should drive. It’s a way to fund the police department by taxing the unlucky, at best. And more likely a pretext to pull people over for looking like they don’t belong. Contemporary traffic engineers understand that you modulate speed with road design, not signs.