A 4-year-old boy has died after he was struck by a vehicle on Monday while crossing the N2 in Brackenhill, near Knysna.The boy was being carried by his mother when they were hit, Western Cape traffic chief Kenny Africa said. The two had just been dropped off by a taxi from Knysna."The mother was seriously injured and is being attended to by medical services," Africa said."The driver's alcohol level was tested and he was arrested after it was confirmed that he was above the alcohol limit."A stop-and-go has been enforced on the road following the accident.