(54)Generally applied zero tolerance schemes for driving under the influence of alcohol, associated with targeted enforcement, have proven to be an effective method for improving road safety. A zero limit on alcohol, not taking into account accidental exposure or exposure having no impact on driving performance, is commonly perceived as the most effective measure to reduce road fatalities and injuries. Zero policies are also being introduced in respect of driving under the influence of drugs. Member States are encouraged to keep and introduce such generally applied zero tolerance schemes in their national law, to which the probationary period scheme should be a complementary measure targeting the over-representation of novice drivers, mostly young people, in road traffic accidents related to drink-driving and drug use.