Here’s a question: Would you want lower gas prices for your car or truck if accepting such an offer could cost you your life in motor vehicle accident? Most people would never accept such a deal, but a recent study suggests that we all make that deal as gas prices fall.

The mechanism is not some grand Faustian bargain, but instead the natural consequence of the change in the price of gasoline. When something like gas becomes more expensive, because Americans drive so many miles every year, we recognize very quickly the impact of $4.00 a gallon gas.

If you drive a large truck or SUV, a 25-gallon tank of gas could cost $100. So people begin to economize. They consolidate their trips to the store with other errands or they make it part of their drive home, rather than going back out later after arriving home.

They also may drive more slowly and not accelerate rapidly away from intersections, all of which reduces gas consumption and reduces the likelihood of a speed-related crash. So higher gas prices reduces our exposure to the activity of driving and makes us drive more safely.

Conversely, cheaper gas increases their exposure to driving more miles, which increases the risk of a car accident. It also encourages driving faster, as the need to drive at a moderate speed to conserve fuel is reduced.

One study suggests that a $2.00 a gallon price drop would translate into 9,000 additional highway fatalities. This would send the current average of about 33,000 traffic deaths well over 40,000, a number not seen since 2007.

This would be extraordinarily high price to pay for cheaper gas, but given human nature, we find it a difficult offer to refuse.

NPR.com, “The Downside Of Cheaper Gas: More Accident Fatalities,” Shankar Vedantam, January 6, 2015