All information in this article is general, and exceptions exist for most, if not all statements on this page.

The current rules in Denmark were made in 1975. All rules for trains on the national network are covered by three rule books:

1. SR75
2. SIN
3. TIB
4. ATC brief ¹⁾
5. Operator's briefs ²⁾

More info to be added, clarifying the relations between the rule books

Danish signals are in principle extremely simple. There are three aspects: Stop, proceed, and proceed, expect proceed. Everything else is built on top of these simple aspects.

For more information, go to Danish Signalling detailed page.

Danish signalling works with stations and lines (outside stations). Special signals and rules govern stations, while lineside signalling outside stations is simpler.

Stations are locations which take part in train movements. ³⁾ In other words, a station is equipped with at least one station entry signal, although many stations also have switches and other signals. A station does not have to have passenger facilities - and some locations with platforms are not part of stations.

The station limit is always the station entry signal (I-signal). From the I-signal, routes can be set to enter the station, usually ending at a platform.

To exit the station the permission can be given either verbally, or via signals (as not all stations have exit signals). At the platform, most stations have so-called PU-signals which mark the start of the exit route. The exit route ends at the exit signal (U-signal), which is technically part of the lineside signalling system outside the station.

Stations are connected by track segments. Only trains are allowed to pass track segments, not shunting movements. There may be passenger facilities and sidings, but no station entry signals (I-signal). There is not much else to say about this.

To prevent speeding passing signals without permission, Denmark has implemented ATC (Automatic Train Control), from Siemens ZUB 123. ATC stops a train if it goes too fast, and if it passes a signal without permission. In theory ATC eliminates the risk of accidents. Simplified versions of ATC exist for cheaper installation.

Nationwide implementation of ETCS is underway, expected to be finished by 2030.

Copenhagen suburban trains (S-tog) have used a different system called HKT (HastighedsKontrol og Togstop, speed control and stop). This offers a continuous stream of information to the train and shorter blocks without the need for more signals.

Network-wide implementation of CBTC has been finished as of September 2022.

Aarhus Letbane uses a mixture of BOStrab and 2/3-aspect signals along with signs from BOStrab and SR75. The safety system is a very basic version of ETCS Level 1. See more.

Copenhagen Metro uses a special ATC⁴⁾ system for automatic operation on lines M1 and M2, while M3 and M4 use a different system for the same purpose.