The '6-hour rule' applies to all drivers and states that if you have been involved in a traffic incident that might be cause for a police investigation, you must not consume alcohol (or other intoxicants) in the first 6 hours following the incident. The reason being that the police in some cases might wish to collect blood samples from those involved if there is any suspicion of the incident having been caused by either party being affected by alcohol or other intoxicants.