UK train driver selection uses timed aptitude tests of concentration, reaction, visual search, memory, rules, and judgement. These tests practise those task formats so assessment day is not the first time you sit this kind of work, under a clock.
A marker runs toward a line. Press Stop when you think it arrives, including after it has gone out of sight.
Why it is useful
You often have to judge when something will arrive. Too early and too late both miss. The harder trials hide the marker, so you keep its speed in your head, including after a stop or a reverse.