How these times are recorded

Every time somebody completes a level of the shunting puzzles they are offered a virtual trophy, and the time on the clock is stored with it. This page shows the quickest time claimed for each level so far.

Drivers are shown by the first three letters of their username, so nobody is identified.

The clock starts the moment you press your first button and stops when the last tram is parked, so thinking time before you begin costs you nothing. The quickest solutions are the ones where several trams are moving at once.

Think you can do better? Head back to the yard and see.

Is there a fastest possible time?

There is, and it can be calculated rather than guessed. Every tram moves one small step every fifth of a second, the points switch instantly, and the tracks only connect up in certain ways – so for any level there is a shortest sequence of movements that gets every tram home.

Because the limit is proven, any claimed time below it cannot have come from playing the puzzle. Those entries are left out of this page altogether, which is why the totals here may not match the number of trophies awarded.

It is a nice piece of mathematics in its own right: the problem is a close cousin of the scheduling puzzles used to plan real railway timetables.