Right Side Day (commonly referred to as Ten-ten) was the day, 10 October 1971, on which traffic in New Cambria switched from driving on the left-hand side of the road to the right. There were two major arguments for the change: * Both Canada and the United States, New Cambria's two closest neighbors drove on the right. * Most New Cambrians drove in left-hand drive (LHD) vehicles. This led to many head-on collisions when passing on two-lane highways, which were common in New Cambria because of its low population and traffic levels.