All of Sweden's neighbours (including Norway and Finland, with which Sweden has land borders) drove on the right, with 5 million vehicles crossing those borders annually.[3]
Approximately 90 percent of Swedes drove left-hand drive (LHD) vehicles.[3] This led to many head-on collisions when passing on narrow two-lane highways, which were common in Sweden due to the fact that the country's low population density and traffic levels made road-building expensive in per capita terms.[4] City buses were among the very few vehicles that conformed to the normal opposite-steering wheel rule, being right-hand drive (RHD).[5]