# Which way is the bus going?

If I'm not mistaken, this is a children's puzzle, but it got me thinking for a while.

The bus is driving on the autobahn. Relative to you, which way is the bus going? Left or Right?

• You forgot to mention what country this is happening in. Commented Jun 3, 2014 at 23:18
• And for completeness to mention that the bus is travelling forwards. Commented Jun 3, 2014 at 23:27
• The bus looks awfully stationary on my screen. Commented Jun 3, 2014 at 23:56
• This question appears to be off-topic because it has multiple different answers as the question is not fully defined. Commented Jun 4, 2014 at 14:23
• The movement "Relative to me" also depends how fast I am moving. Now, "Autobahn" suggests we are both driving. If I see the left side of the bus, I am probably overtaking it. So it must be moving right relative to me. Commented Jan 8, 2015 at 16:18

I saw this problem on a web page once.

The initial thought that most people have is that you can't tell, because the bus is totally symmetrical. However, this misses one important detail that apparently children will imply in their minds more often than adults.

The canonical answer is that this picture of a bus is missing its door, and therefore the bus must be going left, because the door is on the right side of the bus and there's no door visible on the side that's facing you in the picture.

Of course, as Gilles pointed out, depending on which country you're in, the bus could be driving on either side of the road. If you're in Britain or some of the Commonwealth countries, then the bus must be going right, because the door is on the left side of the bus.

And depending on where from the bus you're exiting, the door could be on the top or bottom as well. I've never seen a bus that had its wheels so far below the chassis like on this one, and maybe there's a stairwell that opens from the bottom to let people in and out.

Alternatively, it could be a maglev train given that the car appears to be floating above two round things. A maglev train has doors on both sides. In both of the above cases, you can't tell which way the vehicle is going without further information.

The question was updated to indicate that the bus was driving on the Autobahn. However, a bus on the Autobahn sounds really unsafe, and so we might actually be viewing a tipped-over bus from a bird's eye view (it would certainly explain the detached wheels). In such a case, you still couldn't tell which way the bus was going unless you knew which side of the highway it was driving on.

• You can have a bus with multiple doors, so it's just a bad drawing. But your answer is the answer that will makes the most sense. Commented Jun 8, 2014 at 21:21
• Generally a bus will only have doors on one side because that side is the side facing the curb.
– user88
Commented Jun 8, 2014 at 21:28
• @JoeZ. If the door is facing the curb then it's in the US. On the other hand, if it's in the UK then the door would be facing the kerb. (Other countries may be available) Commented Jul 2, 2014 at 23:56
• Well, if it faces the kerb it's already facing the wrong direction. :P
– user88
Commented Jul 3, 2014 at 0:18

Another way of looking at it, this image looks much like the grill or front face of the bus.

With that in mind I would answer that it is going neither to the left nor the right from my perspective. Relative to me, the bus is advancing directly at me.

• Seeing the round profile of the wheels shows the bus is moving sideways. Commented Apr 2, 2015 at 15:40
• I wasn't the downvote. Commented Apr 2, 2015 at 15:45
• Then I will rephrase :). Since the original question does not state that the two circles are in fact wheels, they could be seen as headlights.
– Easy
Commented Apr 2, 2015 at 15:51

The Autobahn, you say? That means that relative to me, it must appear to be moving to the right.

I'll assume that the bus and I are both driving on the Autobahn. I'll also assume that the bus is, in fact, going either left or right relative to me, since otherwise the question doesn't make sense.

Well, the law on the Autobahn states that you must overtake on the left and you must use the left lane only for overtaking.

So, if the bus is on my left side, it must be overtaking me, so it will appear to move to the right.

On the other hand, if the bus is on my right side, I must be overtaking it, so it will once again appear to move to the right.