A great way to get all the testosterone soaked hard core engineers who hate whining environmentalists wound up is to say something nice about Jimmy Carter, but here is another eminently sensible thing he did: He capped the maximum speed on speedometers in cars at 85 MPH.

Tom Vanderbilt thinks it affects the way we drive. "even knowing that these numbers bear little relationship to reality, we’re affected by the visual display. No matter how fast we drive, the needle is always less than halfway up the dial, indicating there’s still plenty of room for acceleration. That remaining space may even goad us into testing the limits by going faster."

Vanderbilt continues: "Capping the speedometer would remove a theoretical and illegal max to test on public roads. Influenced by the so-called anchoring effect, people are induced to eat more when portion sizes are larger and to drink more when the range of beverage options is increased. (Many consumers eschew the biggest and smallest drink choices at fast-food restaurants, so companies have supersized their “large” choice, thus making the “medium” more palatable, even though it’s bigger than ever.) In the same way, the value of 160 on my speedometer has been shown to influence decision-making."