For motorists who may find themselves in the habit of nodding off at the wheel, here’s something that could help: German scientists have invented a device that uses tiny cameras to track a driver’s eye movements, and triggers an alarm at the first sign of sleep. The scientists say the device could help save 300,000 lives globally every year.
That may be true, but here’s the rub. The Peltzman Effect (named after economist Sam Peltzman) suggests that people adjust their behaviour when faced with increased safety measures, partially, if not fully, counteracting the intended effects. A driver armed with an anti-sleep device may, therefore, be more likely to relax too much, increasing the chances of risky driving. In such cases, the overall risk to nearby pedestrians and other drivers—who would continue to maintain their usual level of watchfulness—is also increased.
The new device may still save some lives, but the risk will remain.