Left-hand drive (LHD) vehicles share higher road accident risks under left-hand traffic because of blind spot areas. Due to low import prices, the number of wrong-hand drive vehicles skyrockets in emerging countries like Georgia, Kyrgyzstan and Russia. I identify the causal effect of wrong-hand drive vehicles on road safety employing a new “backward version” of the synthetic control method. Sweden switched from left-hand to right-hand traffic in 1967. Before 1967, however, almost all Swedish vehicles were LHD for reasons of international trade and Swedish customer demand. I match on accident figures in the period after 1967, when both Sweden and other European countries drove on the right and used LHD vehicles. Results show that right-hand traffic decreased road fatality, injury and accident risk in Sweden by approximately 30%. An earlier switch would have saved more than 4000 lives between 1953 and 1966.

由于盲点区域，左手驾驶（LHD）车辆在左手交通情况下承担更高的道路交通事故风险。由于进口价格低廉，格鲁吉亚，吉尔吉斯斯坦和俄罗斯等新兴国家的反手驾驶汽车数量激增。我使用新的“向后版本”综合控制方法来确定不正确驾驶车辆对道路安全的因果关系。1967年，瑞典从左路交通转向了右路交通。然而，在1967年之前，出于国际贸易和瑞典客户需求的原因，几乎所有瑞典车辆都是左驾。我在之后的时期内匹配事故数字1967年，当时瑞典和其他欧洲国家/地区都靠右行驶并使用了LHD车辆。结果表明，在瑞典，右手交通将道路致死率，伤害和事故风险降低了约30％。较早的转换将在1953年至1966年之间挽救4000多条生命。