Although Iceland had been ruled by Denmark, which officially adopted driving on the right in 1793, it had continued to drive on the left; a plan to switch to right-hand traffic was interrupted by World War II, when the country was under British military occupation, as military traffic was greater than that of civilians.
[2] [3] Iceland's parliament (Alþingi) made the following demand of the government on 13 May 1964:[4] "Alþingi urges the government to initiate as soon as possible research into how best to move the traffic to the right hand side of the road."
[6][7] In addition, Iceland was hosting an increased number of visitors from the United States and mainland Europe.
[5] The Traffic Commission (Umferðarnefnd) was assigned to handle the task.
[9] Traffic accident rates briefly dropped as drivers overcompensated for the increased risk from driving on the unfamiliar side of the road, before returning to the level following the trend prior to the changeover.