To start off, if you're familiar with Hl signals from Dresden Leipzig, then good news! You can expect Czech signalling to feel similar, with main signals consisting of up to 6 lights and having yellow and/or one or two green horizontal lights bars.
Let's hand over the the Vector Simulations team for more information and details about how to operate the signals across the line:
Vector Simulations: "LVZ and LS90 are both line safety systems, which means that they get informations about signals at any point through frequency modulated voltage in rails. This signal transmission system is equipped mostly only on electrified main lines and not present at the Liberec - Stará Paka (- Pardubice) route. As LS90 is a modernised version of LVZ (also called LS IV), they behave very similarly. If there isn’t any signal being transmitted, it works only as a vigilance control device, similar e.g. to SIFA. If there is any transmitted signal, it will adjust times between vigilance checks accordingly. Vigilance checks then start after the driver releases the direct brake, once the brake cylinders pressure drops under certain threshold (generally 1.5 - 1.8bar)."
- Green code (only for Free signal) – vigilance is not required if the train is travelling under it’s construction speed. If in any case the train would exceed that, the safety system would require vigilance checks until the train slows down again.
- Yellow code (Caution or Expect speed restriction) – vigilance is being checked if the train is travelling faster than 120 km/h
- Yellow circle code (for any signal of speed reduction) – vigilance is being checked if the train is travelling faster than 40 km/h
- Red code (Stop, Call On or Repeated Caution signals) – vigilance is required at all times

VS: "Sometimes there can be some outside interferences present, e.g. high voltage powerlines running nearby the tracks, the safety systems can sometimes detect false signals. LVZ system was quite prone to this and player can see this in-game. LVZ equipped locomotives have also transmission frequency switch, where driver can select between 50 Hz and 75 Hz frequencies if a track-side signals say so. Newer safety systems do this switching automatically. 75 Hz frequency is used to eliminate most of powerline interferences, because even at a few hundred meters distance from the tracks they still can interfere if both powerline and code transmission frequencies are 50 Hz."

"Distant signals then have only yellow and green lights. In some cases where visibility is limited or it is expected that a train would stop between the distant and main signal, there can also be placed a repeating distant signal. Those have the same lights as a distant signal, but have one more white light, which tells the drivers that this is an aspect of a repeating distant signal. Distant signals can also be integrated with main signals, e.g. in stations, where entry signal would work as a distant signal for the next signal, most of the times being the exit signal."
Here are some of the signals players will most often see at the Liberec - Stará Paka route:

- White light – shunting movements allowed, valid only for a shunting movement
- Blue light – shunting movements forbidden, valid only for a shunting movement
- Green light – free
- Yellow light – caution
- Red light – stop, also forbids any shunting movements past the signal
- Slow flashing yellow light – expect speed restriction 40 km/h
- Two yellow lights – speed restriction 40 km/h and caution
For those unfamiliar with the two locos coming with the route, you can find the isolation switches for the safety systems in the engine room for the Class 750, and in the Class 843, the switches will be below to the right of the driver's seat.
Class 750 Cab & Engine Room


Class 843 Cab

VS: "We have tried to maintain the highest levels of accuracy of the tracks itself, so players can expect to see accurate rail profiles with real curve radiuses, transition curves and gradients. We have created a completely new set of Czech infrastructure elements, including very detailed junctions."
