Gone are the days when the interlocking system would stop your journey in SubwaySim Hamburg! We have decided to rewrite the entire signalling and interlocking system from scratch.

Since the release of SubwaySim, some of you have repeatedly reported problems with the current interlocking system - like permanently red signals, collisions with AI trains and incorrectly set points/switches. All of these issues are now a thing of the past!

But how exactly does our new interlocking system work? In short: almost exactly like a real signalling system. Put simply, five steps are necessary before the train can set off:
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First, the start and destination signals are determined. A route must always end at a signal.

Next, we check which train should receive clearance next. It is important that the trains always follow the correct sequence, especially when departing from siding tracks on the line.

Then we check whether the track is really free of vehicles. As soon as a vehicle is in the way, the signal of course cannot change to green.

If all these conditions are met, the points/switches are set and locked.

Shortly afterwards, the signal and the corresponding advance signal will turn green.

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All these steps are now simulated correctly - and must also be taken into account by the timetable accordingly. Thanks to all these new features, there are now also two new signals, which we would like to introduce to you below.



New signal: Advance Signal with Speed Indicator

Actually, many of you have requested this signal. Thanks to it you will be notified when the main signal displays a speed limit - in this case 30 kph. This will allow you to slow down in time before the new speed limit becomes valid.



New signal: End of Route

The special feature of this signal is that you are never allowed to drive past it. It is only located at certain platforms. With our new signalling system, we also had to install this signal.

The reason: As mentioned above, our routes must always go from signal to signal. For sidings, the buffer stop counts as the destination signal, but what if we want to enter a platform track against the direction of travel - for example because we want to turn around there?

In this case, we need a signal that tells us the maximum distance we are allowed to travel. And that's exactly why there is this little red light on many platforms, such as here on Saarlandstraße at platform 2 (heading towards Barmbek).


We hope you appreciate these deep insights into the development process behind the upcoming MEGA Update and we're looking forward to your responses!