# Should the steering wheel of car be on right or left? [closed]

What is the user experience of steering wheels placement based on? I recently visited US and they have steering wheel on the left whereas back in asian countries we usually have it on the right. What are the factors that decide its placement?

• "What are the factors that decide its placement?" Which side of the road you drive on?.. Commented May 18, 2016 at 13:15
• added an image,hope that clarifies the question. Commented May 18, 2016 at 13:21
• Have you done any research before posting this question?
– JonW
Commented May 18, 2016 at 13:37
• I haven't really, I am travelling and have limited internet connectivity but was curious to find it out,so just posted it out here. Commented May 18, 2016 at 13:48
• I'm voting to close this question as off-topic because the reasons being are well understood and quickly obtainable through a Google or Bing Commented May 18, 2016 at 22:44

I'm pretty sure that has to do with the side of the road you drive on. You didn't specify which Asian countries, but as a quick test I looked at Chinese car interiors (wheel on left) and Japanese ones (wheel on right), and that conforms to right/left side of the road. Red = Right on road, Blue = Left on road. Via wikipedia.

The question then becomes: 'why is the wheel opposite to the side of the road we drive'.

I don't know if there's a historical reason. I do know that it gives (on average) a better view of the road:

left image = steer opposite to road side, right = steer at same side we ride.

The first thing you'll notice is consistency. Driving in the middle of the road will give the same distance when looking through a curve. When you are on either side of the road, you can see further if you're on the outer curve, but less far if you're on the inner curve. From a usability standpoint consistency is good. So we try to ride as close to the middle of the road as possible.

Second thing you might notice is that how much more/less you see. In my first example you can see the middle of the road during an outer-curve-turn, and the side of the road during an inner-curve turn. In the second example, you can see a bit more (about 15 pixels) during an outer curve, but considerably less (about 45 pixels) during an inner curve. So on average, you're seeing more.

More vision + more consistency = superior.

Another point is passers-by. (both coming towards you and those overtakinh you) If you drive on the right, people will pass on the left, so you need to pay more attention to the left side of your vehicle.

• It took me a while to figure out what was going on in that second image - I was about to get upset about the road only curving to the right. Closer inspection revealed all though! ;) - What was the source for that image? Commented May 18, 2016 at 14:07
• @AndrewMartin Yeah driving from bottom to top is a right curve, top to bottom is a left curve. A bit cluttered, but otherwise there'd be so many similar images! I made the second chart myself just for this, but feel free to use it elsewhere. The map is from wikipedia, will edit that in. Commented May 18, 2016 at 15:28

It is simply that countries where you drive on the right side of the road the driver will be positioned on left side of the car. Countries where you drive on the left side of the road the driver will be on the right.

In effect this means that in countries with right-hand traffic, the driver and the vehicle controls would normally be located on the left-hand side of the vehicle. In other words, the vehicle would be described as left-hand drive, LHD. The reverse appears with left-hand traffic, which has right-hand drive (RHD) vehicles.

Wikipedia: Right- and left-hand traffic

Now as to why? It gives the driver the best view of the road: (same article)

manufacturers placed the driving seat on the side closer to the centre of the road to give the driver the longest possible line of sight in traffic

So it stemmed from the UX of the drivers view of the road, but nowadays it is simply the law not a UX decision as to where the driver sits.

In the late 1700s, however, teamsters in France and the United States began hauling farm products in big wagons pulled by several pairs of horses. These wagons had no driver’s seat; instead the driver sat on the left rear horse, so he could keep his right arm free to lash the team. Since he was sitting on the left, he naturally wanted everybody to pass on the left so he could look down and make sure he kept clear of the oncoming wagon’s wheels. Therefore he kept to the right side of the road.

List of left- & right-driving countries

The trend among nations over the years has been toward driving on the right, but Britain has done its best to stave off global homogenisation. With the expansion of travel and road building in the 1800s, traffic regulations were made in every country. Left-hand driving was made mandatory in Britain in 1835. Countries which were part of the British Empire followed suit. This is why to this very day, India, Australasia and the former British colonies in Africa go left. An exception to the rule, however, is Egypt, which had been conquered by Napoleon before becoming a British dependency.

• If there was a compelling reason to drive on the right, what reason did Britain have for doing differently? A huge population of left-handed wagon drivers? The answer doesn't give the reason.
– user67695
Commented Nov 27, 2017 at 17:31

This is a historical issue that goes back to horse-drawn coaches.

In the UK, coaches would pass on the left so that the coachman (driver) could fend off any attack from the passing coach with their stronger right arm. (Why do some countries drive on the left and others on the right?)

In the US (and other countries) The idea was that if coaches passed on the right it would be more difficult for attackers to attack with their weaker left arm.

Along with this goes the physically wider field of view you get from being closer to the centre of the road - thus, cars that drive on the left have their driver controls on the right and cars that are built to drive on the right side of the road have the controls on the left.

• I guess that once guns became commonplace, a shoulder-width change of distance was not important, but by then, the traffic patterns had been set. It is rather disappointing to find that not only was such a stupid reason chosen for which side to drive on, but that there are two equally stupid arguments choosing opposite sides. Maybe all UX should reduce to choosing the way that someone is less likely to attack? Or, the way that is easier to defend... Shoot! I can't make up my mind!
– user67695
Commented Nov 27, 2017 at 17:29