The joke

It is a standard April Fools' Day joke that will get dredged up once every few years, and goes something like this:

Ireland is considering amending all of its roads from left-hand drive to right-hand drive so it can be more in line with European standards. However, it will be done on a phased basis where only heavy goods vehicles will drive on the right for the first six weeks, after which all vehicles drive on the right.

However, more than 50 years ago, in 1967, Sweden implemented this change (though it did everything at once, not on a phased basis), switching all traffic lanes from left to right. In a 21st century world, where reducing lanes on a motorway can be a difficult task, switching a country's direction of traffic, (with more than 200,000 kilometres of roads), wasn’t something that could be achieved overnight. In fact, it took more than two years to put in place.

The history

Prior to 1967, all vehicles in Sweden drove on the left despite all cars being calibrated for right-hand drive (steering wheels on the left). As all other countries it bordered - Finland, Norway and Denmark - drove on the right, this also created an issue of driving consistency in the region. [caption id="attachment_45553" align="alignright" width="258"] Extent of Kalmar Union[/caption] So, how did Sweden end up with left-hand drive in the first place? One of the reasons for this was the Kalmar Union; a union formed between the Baltic States in the 1400s to act against German expansion northwards. However, Sweden was the first to break away from the union in 1523 and thus started its own independence from the rest of the Baltic States. While Sweden later rejoined the Kalmar Union, it was the first decisive moment when it moved away from these other countries, forming its separate identity. At the end of the Kalmar Union, Sweden lost ownership of Finland in 1809 to Russia (a right-hand driving country) with most of Finland then moving to right-hand drive in 1858. The next stage of movement to right-hand drive was Napoleon Bonaparte. While it’s never been directly attributed to him, most of mainland Europe converted to right-hand drive during the Napoleonic era (1799-1815 approximately). While the majority of transport at the time was by horse (Karl Benz wouldn’t patent his car until 1886), this was a pattern of development with a large number of people travelling on the right-hand side of roads. The theory went that as 85 per cent of people are right-handed, they held the bridle of a horse on their right-hand side, and walk along the centre of the road for direction. Meanwhile in Britain, a more feudal country in more ways than one, walking on the left was the standard as it was believed this avoided swords clashing, which would typically hang to the left of one’s waist. Funnily enough, Sweden also appears to have laws as far back as 1734 relating to this issue (statistics on sword-related brawls are difficult to find). [caption id="attachment_45554" align="alignright" width="300"] Paris Street in 1889 (©[/caption] Almost a century later, at the 1920 Paris conference, a decision was made to change most of mainland Europe’s roads from left to right, despite only a slight majority driving on the right. So, over the next 30 years, Czechoslovakia, Hungary, Italy, Portugal, Slovakia, Spain and Ukraine all went through some form of calibration of driving from left to right. This was quite feasible at the time as the only number of registered vehicles in Europe was approximately 500,000 vehicles and many of these countries still used horses as a primary form of transport. However, with the advent of increased motorised vehicles after the Second World War, and increased motorways, switching to the right-hand drive in Sweden was going to be difficult. In 1920, the number of registered cars in Sweden was 80,000 but, by 1960 this figure was at almost 1.2 million vehicles.

Referendums and campaigns

With all countries around them driving on the right and all vehicles in Sweden being calibrated to right-hand drive, a referendum was held in 1955 to see if switching all roads from left to right was a good idea. Despite government support, the public rejected this by 82.9 per cent to remain driving on the left. No matter, mounting pressure from the European and Nordic Council led to a 1963 decision to change to the right-hand side. How was this going to be done? Rather than make it a quick exercise over a bank holiday weekend, a mass four-year campaign began to inform the public and plan the changeover. This included establishing a ministry (the right-hand traffic commission), monthly bulletins, planning, advertising and even a hit pop song. As more than 200,000km of roads had to be converted, some signage and infrastructure changes had to be made. To make this a simpler changeover, poles and signs were erected in advance of the changeover date but wrapped in black plastic so this could be quickly implemented on the day itself. Similarly, lines were also painted on the ground and covered with black tape. These new lines were white as prior to Dagen H, Swedish roads used yellow lines. Bus stops also had to be constructed on the opposite side of one-way streets. Bus modification also had to take place with more than 1,000 new buses purchased with doors on the right-hand side and another 8,000 older buses fitted with doors on both sides. On the final day, more than 20,000 people were working on the road network converting all items, including 300,000 signs to right-hand drive calibration.

Högertrafikomläggningen" (Dagen H Day)

On September 3, 1967, everyone was going to the changeover where people would move to the right. This day became known as Dagen H (H day) with the Swedish for right-traffic being Högertrafik. This day included banning non-essential traffic from roads between 1am and 6am. Any vehicles that were on the road during this time had to come to a complete stop at 4.50am and then slowly and carefully change to the right-hand side and then proceed 10 minutes later at 5am. This traffic ban was extended in urban areas where signals had to be calibrated further during the day. [caption id="attachment_45556" align="alignright" width="210"] Dagen H poster at the time[/caption] On the day itself, only 157 minor accidents were reported, of which only 32 involved personal injuries. Over the next year, there was a reduction in collisions. Part of this was attributed to safer overtaking as vehicles had right-hand drive cars and had greater forward visibility. Motor insurance claims over this period dropped by 40 per cent over the next two weeks - although this returned to normal within two months. However, all metro and railway systems stayed on the left-hand side and continue to this day. During 1967, there were 236 fewer road deaths than the previous year. The result of Sweden switching from left to right-hand driving led to a slight drop in collisions over the next few years, which could have been attributed to the campaign. However other factors, such as increased seatbelt wearing, motorway expansion and reduced drink driving may also have been contributory factors. Since this permanent change, only Iceland has attempted something similar, with a switch to driving on the right taking place in 1968. It would be more difficult to do it today, with almost five million cars on Sweden’s roads as opposed to the 1.8 million in 1967.

Could Ireland or any other country do it today?

While obviously difficult, it would not be an impossible task for Ireland to attempt something similar. In 2005, almost 50,000 signs were changed seemingly overnight in the country when the switch was made from mph to km/h; however, changing the entire network to right-hand drive would be another level of difficulty. Similar to Sweden, there are more than 100,000 kilometres of roads in Ireland that would have to be changed. There is also the matter of stopping cars overnight, which may have a minor economic effect, especially in more hectic economic times. Other elements of the roadway, such as signals, motorway gantries and road detectors would also have to be changed. The key difference is that Sweden already had cars calibrated for right-hand drive. Furthermore, the actual benefits of this would be an issue. While Sweden had a road safety and car network argument in 1967, Ireland already has one of the safest road networks in Europe (currently seventh in EU country rankings), so spending millions to bring about a road network change without any monetary or safety benefit would be difficult to justify. Also, even after amending all the signs, traffic signals, IMS signs, loop detectors and bollards, we would then have to switch all of our 2.1 million cars, 32,500 public service vehicles, 719 school buses, 350,000 goods vehicles, 981 hearses, and three Lamborghinis (car not tractor) to right-hand drive. This would either need a lot of downtime or a mass order of new cars to enter the country, with older vehicles being exported or calibrated to right-hand drive. In the meantime, we could just use bicycles or tractors while listening to the same Imelda May song about why driving on the right will be totally worth it. Or, we could do a temporary trial for two weeks... Author: Hugh McCarthy, MIEI CIHT, chartered engineer, is vice-chair of the Engineers Ireland GB Region