Symmetry minute

The symmetry minute is a significant time point in the clock face timetables used by many public transport operators.

At this point in the cycle, a train in a clock-face timetable meets its counterpart travelling in the opposite direction on the same line.

However, at the transition between two networks or lines, it is expedient to set uniform symmetry minutes, to create a symmetrical connection relation.

For the long-distance cycle systems of ÖBB and SBB, the Forschungsgesellschaft für Straßen- und Verkehrswesen für Deutschland (Research Association for Roads and Traffic for Germany) recommends minute 58, so a four-minute minimum connecting time results in a departure at minute 0.

The following table shows the departure times in opposite directions for an hourly cycle, using the 58½ symmetry minute (the most common in Central Europe).

Shortly before every full hour in central European countries using a clock-face timetable , many trains meet and pass the corresponding train in the other direction.
A rail net on an hourly cycle with symmetry at minute 0