How can mandatory penalties and a high chance of conviction discourage drunk driving?

The theory of general deterrence suggests that mandatory penalties and a high probability of conviction discourage drunk driving by influencing the rational decision-making process of potential offenders.1

Because most individuals are assumed to be rational, they weigh the potential rewards of an action against the risks of being caught, prosecuted, and sentenced. When laws regarding driving under the influence are paired with mandatory consequences and a high likelihood of conviction, the perceived risk of punishment increases, which can effectively dissuade a wide population from committing the offense.1

This approach relies on the principle that ensuring legal consequences serves as a deterrent by making the cost of the crime more certain. While deterrence theory can be difficult to validate due to various intervening factors, evidence indicates that these specific measures can have a temporary deterrent effect on the prevalence of drunk driving.21