Ever wondered why we drive on the left? Or how many people could fit in a Mini? Perhaps you wonder about more practical things which may directly affect you, such as which cars are more likely to fail an MOT? Well, we've tried to answer just a few of the questions that sometimes crop up in our office: Why do we drive on the left whilst most other countries drive on the right? About two-thirds of the world's countries drive on the right. But it's generally accepted that road traffic began on the left, and there's evidence for this that dates back to Roman times that supports this. As more people than not are right-handed, it makes sense that someone on horseback would favour riding on the left, as that means they would be more likely to greet or attack on their good side. But road users started tending to the right during the 1700s. A common myth is that countries that Napoleon conquered switched to the right, on account of his being left-handed. However, the more likely reason for the switch was to favour the postillion (or ‘post boy'), who was the driver of coaches drawn by several horses. The horses were set in pairs, and the postillion would ride the front horse on the left-hand side, as horses were trained to be mounted from the left. So, to avoid collision with other coaches, it was more manageable to ride on the right. This switch began in countries such as France and the United States. The twentieth century saw a bit of a domino effect, as more and more countries swapped to the right - principally as the uniformity makes border crossings with neighbours easier and less dangerous. How far does the average person drive in their lifetime? Back in 2008, we did a bit of research and discovered that the average British driver clocks up around 507,000 miles in their lifetime. So quite a bit then. This would comfortably cover a trip to the moon and back, in fact. I say "in fact"... Not that you could actually do this. What's the most popular colour of car? Across the world, the most popular colour is silver. Which includes charcoal. Or any shade of grey, it appears. Black comes in second place - which suggests the roads aren't quite as colourful as they could be. What's the fastest speed at which anybody's been caught driving in the UK? In the United Kingdom, the fastest anyone's been caught driving is 197mph, Kazuhiko ‘Smokey' Nagata in 1999. He did this on the A1(M) in a Toyota Supra he brought over from Japan just for this purpose, and was subsequently arrested. Apparently, he was only fined £155 plus court costs, and banned from driving in the UK for a month. I wouldn't recommend trying it though - you won't be so lucky. You can watch this loon in action on YouTube, which is worth doing just for the unintentionally hilarious commentary. Which car is most likely to fail an MOT? It's only recently that the Vehicle and Operator Services Agency (VOSA) has made this information available, as a result of a Freedom of Information request made by the BBC. The raw data is 1,200 pages long, so good luck if you intend to read that. However, some readers have made efforts to present this information in an orderly fashion, including one spreadsheet which orders the most common cars and small vans in order of failure rate, with a breakdown including make, model and age. You can assess this for yourself on the BBC Open Secrets blog here, although it's important to bear in mind that other factors will affect the rate of failure, such as the car in question's mileage, and - of course - how much (or moreover little) care and maintenance the driver has afforded the vehicle. How many people can you fit in a Mini? It depends whether you mean a classic Mini or the new design. 21 Malaysian students squeezed themselves into the former in June 2006. The world record for the number of people you can squeeze into a new Mini is 24, and was set in Auckland in July 2009. If you're thinking of getting into the Book of World Records yourself, Guinness requires that participants are at least 18 years old and five feet tall. Plus, you can't take out the seats, and have to be able to close the doors and windows on completion.