Risk compensation

Risk compensation is a theory which suggests that people typically adjust their behavior in response to perceived levels of risk, becoming more careful where they sense greater risk and less careful if they feel more protected. This effect is usually small in comparison to the fundamental benefits of safety interventions, but it can reduce the overall benefits or even result in increased risks.

For example, it has been observed that motorists drove closer to the vehicle in front when their vehicles were fitted with anti-lock brakes. There is also evidence that the risk compensation phenomenon could explain the failure of condom distribution programs to reverse HIV prevalence and that condoms may foster disinhibition, with people engaging in risky sex both with and without condoms.

By contrast, shared space is an urban street design method which consciously aims to increase the level of perceived risk and uncertainty, with the intention of slowing traffic and reducing the number and seriousness of injuries.