Zero tolerance policy is a policy where no alcohol is allowed for drivers who are under a certain age or who have recently obtained their driver's license. This means that if you fall under this group of drivers, you must not have consumed alcohol before driving.
In some countries, such as Belgium, Germany, the Netherlands and France, there is a zero-tolerance policy for novice drivers. This means that if you are under the age of 21 or have only recently obtained your driver's license, you must not have consumed alcohol before driving or you could be fined or have your driver's license revoked. Zero tolerance also applies to taxis, bus drivers, etc (in the case of transport by third parties for professional purposes).
The goal of a zero-tolerance policy is to increase road safety by protecting young or novice drivers from the dangers of driving under the influence of alcohol. It also aims to help young drivers develop responsible drinking and driving habits.
It is important to note that the zero tolerance policy may vary in each country and it is therefore advisable to check the specific laws and regulations in your country.