Drivers in Samoa in the South Pacific are preparing to switch from driving on the right side of the road to the left after a rule change by the government, BBC reported.
The move survived a late legal appeal by the protest group People Against Switching Sides (Pass), who have argued that it will cause chaos.
The government brought about the change to bring Samoa into line with other South Pacific nations.
It is the first country since the 1970s to bring about such a change.
The switchover is due to start at 0550 on Monday (1650GMT), when radio messages will broadcast telling drivers to stop and to prepare to overturn 100 years of motoring tradition.
At the top of the hour will follow a second instruction: to move from the right to the left side of the road.
Import driver
Critics of the plan claim it will bring mayhem to the highways and byways of this remote South Pacific nation.
Bus drivers have also protested that their doors will now open on the wrong side, in the middle of the road.
But the Samoan government introduced the change to end its reliance on expensive, left-hand drive imports from America.
It hopes that Samoan expatriates in Australia and New Zealand will now ship used, more affordable vehicles back to their homeland.
To minimise the chaos, a two-day national holiday has been declared to keep cars off the road, and prayers have been said at the country's churches in the hope of blessing the changeover.