Nation that switched from right- to left-hand traffic in 2009 Crossword Clue

 The answer to the crossword clue "nation that switched from right- to left-hand traffic in 2009" is Samoa.

Samoa is an island nation in the South Pacific Ocean. It had been driving on the right side of the road since it was a German colony in the late 19th century. However, in 2009, the government decided to switch to left-hand traffic in order to harmonize with its neighbors, Tonga and American Samoa.

The switch to left-hand traffic was a major undertaking. It required the government to change all of the road signs, traffic lights, and markings. It also required businesses to change the way they operated, such as moving the driver's side of their vehicles to the other side.

The switch to left-hand traffic was not without its challenges. There were a number of accidents in the first few days, as drivers got used to the new system. However, the government has said that the switch has been a success overall, and that it has made roads safer in Samoa.