This trilingual Swiss site may be helpful. It distinguishes between special or regularity tests and hose or tube tests, with the latter being very short and therefore tricky.

Spéciales (special or regularity tests)
Spéciales are kept secret. The starting time of the Spéciale is either entered on the log sheet or will be handed out just before the start.
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Hose tests
These tests – unlike the Spéciales – are completed on very short stretches (max. 100 m). The time is measured by pressure on tubes positioned on the ground.
At the start of a "tube test", an information table indicates the required time (in seconds) and the distance to cover (in meters). The pressure of the front wheels on the tubes that mark the start and finish lines will register the time electronically.
Such tests can also occur "flying" (i.e. whilst you are driving with the normal traffic flow). You are expected to pass the test in the time provided without slowing down hard or coming to a complete stand still. These tests are specially marked (yellow and green flag together with required time for the test).
Deviations from the required time over or under target will be penalised with 1 penalty point per 1/10 sec.
https://www.raid.ch/en/winter-raid/winterraid/timekeeping-wi...

Compare this description of the Targa Florio Historic Rally

At the start was the first of several skill tests which consisted of driving over timing hoses in a planned fashion.
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Later in the morning, before we got lost, we arrived at another check point and skill test with the rubber hoses across the road.
https://www.ferrarichat.com/forum/threads/historic-targa-flo...