The commuter's journey

A man takes a train to work every weekday morning and a train back home again in the evenings. He always walks from his house to the station in the morning and back again in the evening.

He lives some way from the station, but luckily there is a shortcut he can take down an alleyway that runs between the railway tracks and a tall building. High railings along the side of the alleyway prevent people from trespassing on the tracks.

Like many people, he sometimes leaves home too late and has to hurry to the station to make sure he's in time for his train. Despite the fact that the shortcut would cut several minutes off his walk, he often chooses not to take it, even if this means he ends up missing his train.

In the evening, however, he always takes the shortcut through the alleyway, despite the fact that it's poorly lit.

Can you explain the man's behaviour?

For the sake of clarity, here is a map of the scene:

================ Railway tracks =============
++++++++++++++++ Railings +++++ | Station |
Alley           ---------
---------------- Outer wall of high building


Some hints:

The tracks do not pass down or cross the alley at any point, and the man is in no danger from the train at any time.

The man gets onto the train in the normal way, by walking into the station, going onto the platform and then boarding the train when it arrives.

Some mornings, he is more than happy to walk down the alley to reach the station.

The man's behaviour is the same all year round, even in winter, but at that that time of year he is more likely to take the shortcut.

The man's behaviour is unusual: most people would happily take the shortcut in the morning.

Everything in the description is relevant to the answer.

Z <-

• Congrats to user2390246 for solving this. Solvers might be interested to know that this puzzle was inspired by my journey to work, which is exactly as described in the puzzle. However, I am not the man in the puzzle, and I am able to take the shortcut every morning. – paolo Oct 7 '16 at 16:36

8 Answers

I think perhaps

The man is epileptic. In the morning (assuming it's not cloudy) the sun shines through the railings. (We can tell that the sun rises towards the "top" of the map as there is a compass arrow at the bottom of the question: when viewed on its side, "Z <-" is an arrow pointing to N. Credit to @LogicianWithAHat for noticing this.) As he walks past, the railings cause a flickering effect on his eyes which risks triggering a fit. In the evening, the sun shines from the opposite direction and he does not have a problem.

• Well done! You got it. Can you explain the meaning of the "Z <-" hint? – paolo Oct 7 '16 at 14:57
• Is it a compass arrow, showing North to the left? (rotating Z gives an N)? This shows that the sun rises at the 'top' of your map (east), shining through the railings on a walk to the station – LogicianWithAHat Oct 7 '16 at 15:07
• Yes, that's it. – paolo Oct 7 '16 at 15:09
• @LogicianWithAHat Good spot! I have incorporated that into the answer. – user2390246 Oct 7 '16 at 15:19
• @paolo Nice puzzle! My only quibble is that the sun will only shine through the railings for a short period each day soon after sunrise. In most parts of the world, that time will vary according to the time of year and so won't always coincide with the man's commute. Unless he lives near the equator, in which case there won't be much in the way of "winter" and "summer" :) – user2390246 Oct 7 '16 at 15:24

I think that

The high building reflects a lot of light, and it's very bright and hot and otherwise uncomfortable to take that path on a bright morning.

He takes it more often when he's not late because

The sun isn't up yet, or at least not to an angle that makes the shortcut unbearable

And he still takes it sometimes because

It's cloudy or rainy, which makes the trip much less relatively unpleasant.

In the evening, however

The sun is behind the building, and so it's nice and cool on his way home.

• You're very close. However, there's something mentioned in the question that you haven't taken into consideration. – paolo Oct 7 '16 at 14:34
• Are we thinking of Rafael Viñoly? Great answer. – Anthony Geoghegan Oct 7 '16 at 14:38
• I've added another hint: he behaves this way even in the winter, when it is cold. – paolo Oct 7 '16 at 14:47
• The man suffers from albinism? – Anthony Geoghegan Oct 7 '16 at 14:55

An idea:

The man is obsessive compulsive and/or superstitious. When the sun is rising behind the high railing, it projects a pattern of lines in shadow onto the alleyway ground. The man cannot bring himself to step on the lines, so he avoids the route all together. When it is either cloudy or dark, this phenomenon does not occur, so he can safely walk the alleyway

The shortcut is 'inbetween the railway tracks and a tall building'.

If he leaves late in the morning and the train leaves without out him, if he goes down the shortcut he could get hit. The high railings mentioned aren't necessarily on his side of the railway, as it is next to a building

However in the evening, the train has gone before him so he can walk down the path without worry that the train will hit him

• But it says "High railings along the side of the alleyway prevent people from trespassing on the tracks", so surely they must be between the alleyway and the tracks? – Rand al'Thor Oct 7 '16 at 13:28
• Interesting. However, the train doesn't pass down or across the shortcut, and the commuter is protected from the trains by the railings. I've added a map to show the layout of the scene. – paolo Oct 7 '16 at 13:36

There's a coffee place that he likes on his way to the station, that isn't along the shortcut

Or

He's the conductor and/or driver, and something of a sadist. If he's running late, he'll make sure everyone else is too!

More likely

The station has a bus that goes to it, which he takes if he's running late. Not being a pedestrian, the bus cannot fit through the alley without causing multiple casualties

• Not what I'm thinking of. The description and map of the scene are relevant. – paolo Oct 7 '16 at 14:15
• “He always walks from his house to the station in the morning and back again in the evening” (empahsis mine). – Anthony Geoghegan Oct 7 '16 at 14:33

There is a steep uphill slope in the allyeyway going from home to the station and he would be tired or sweaty when he reached work.

The high building is in fact a public building with a café or with public service offices or whatever in it, and it has entrances on both sides. When the commuter is on time in the morning, the building is not open yet, but it will open soon, and passing through it (instead of having to walk around it) he could save some time.

When the train stops in the evening he can use the railings to reach the alley directly through the trains bogie. Its not possible during the day due to 2 reasons -

1. He has to tresspass in front of a big day crowd
2. He has to climb the railings