Many people who visit the United Kingdom wonder why do people there drive on the left. Gareth Edmunds, 59, from Bristol, said his theory is that its something to do with times gone by when if you met a stranger on the road youd pass on the left so your weapon arm was on their side. He also agrees with Stephen Laing, curator of the British Motor Museum in Warwickshire who believes that theory dates back to Roman times. "Most people are right handed, naturally mount a horse from the left and so need their right hand free for combat," he elaborates. "Roman armies marched on the left hand side of the carriageway and this is a convention that stayed." Motoring author Giles Chapman said Britains Highway Act of 1835 enshrined driving on the left in law for this country and its colonies. "The rule was exported, for example, to Japan, where British engineers planned its railways to drive on the left, leading to a similar edict for road vehicles," BBC reported. Richard Mace, 63, who lives near Chatham in the south-east of England, said he had always been curious as to why they drive on the right in the US. "The reason I have been given goes back to when wagons were drawn by oxen," he said. He could be on the right track. In the late 1700s wagons pulled by horses arranged in pairs became increasingly popular, Fraser McAlpine wrote for BBC America. The driver sat on the back of the rear left-hand horse, to whip the others right handed. The best way for one wagon to pass another without banging wheels was the right hand side of the road, according to McAlpine. The government examined such a plan in 1969, two years after Sweden switched to driving on the right, according to BBC. Its report rejected the idea on grounds of safety and costs. In 1969, the financial burden of making the switch was calculated by the government to be £264m. That equates to about £4bn in todays money. But given the huge advances in infrastructure since 1969 this would now be an extremely conservative estimate. Stephen Laing, curator at the British Motor Museum, said he could not see Britain swapping sides. "I think we are kind of set in our ways," he said. "The infrastructure is built around driving on the left hand side. I cant really see that changing in the future." The Department for Transport said: "We do not have a policy on this because its not something we are interested in at this time.