In 1967 Sweden switched, overnight, from driving on the left to driving on the right, stopping almost all traffic in the entire nation at a set hour so that every car, bus and lorry could cross to the

Key Points:

• On September 3, 1967, Sweden switched from driving on the left side of the road to the right side in a coordinated national event called Dagen H, involving nearly 2 million vehicles stopping and then simultaneously switching sides at 5 a.m.
• The change was motivated by safety concerns, as Sweden was the last left-driving country in mainland Europe, surrounded by right-driving neighbors, and most cars were left-hand-drive, making overtaking dangerous.
• Despite a 1955 referendum where 83% of Swedes opposed the switch due to cost and safety fears, the government proceeded with extensive preparations including road reconfigurations, public education campaigns, and traffic bans to ensure a smooth transition.
• The switch was executed without major incident, with only 157 minor accidents on the day and no fatalities, and accident rates remained lower in the following weeks, leading to increased public support for the change.
• Studies later showed that the switch likely saved thousands of lives by reducing wrong-side driver misalignment accidents, and the change has remained permanent with no serious calls to revert back.